Observatorio ARVAL

Astro Links


Contenido (Contents):


Use Ctrl-F (Find) para encontrar palabras en esta larga y frecuentemente actualizada página (cerca de 1.100 enlaces). Busque por "Castellano" y "Español" para localizar las páginas en este idioma fuera del área de "Países".

Use Ctrl-F (Find) to find words in this frequently updated long page (some 1,100 links).

El Web está hecho de enlaces. Google los cuenta. El rango de una página en el Web (en el Google Toolbar y Google Search) es directamente proporcional a esta cuenta. Enlace hacia sus sitios favoritos desde sus paginas en el Web!

The Web is made of links. Google counts them. The rank of a Web page (in the Google Toolbar and Google Search) is directly proportional to this count. Link to your favorite sites from your Web pages!


Space Telescope Science Institute (STScI):
Space Telescope Science Institute (on the campus of The Johns Hopkins University (Baltimore, Maryland) and operated by the Association of Universities for Research in Astronomy (AURA) for NASA. Operates the science program for the Hubble Space Telescope and will conduct the science and mission operations for the James Webb Space Telescope)
STScI Public Information Home Page (to share scientific knowledge of the universe)
Amazing Space (Hubble Space Telescope's discoveries to inspire and educate about the wonders of our universe)
Digitized Sky Survey (MAST DSS) (all-sky photographic surveys conducted with the Palomar and UK Schmidt telescopes)
Exploration In Education (ExInEd) (Electronic PictureBooks, Tutorials, and Reports)
Faint Images of the Radio Sky at Twenty-centimeters (FIRST) (The VLA FIRST Survey)
Hubble Heritage Project (A photo album of some of Hubble Space Telescope's most stunning views of the universe)
HubbleSite (from the STScI Office of Public Outreach)
Hubblesite - Explore Astronomy (Explore some of the marvels that lie within our cosmic neighborhood and beyond)
 - Black Holes: Gravity's Relentless Pull - Introduction
 - Tonight's Sky (Monthly stargazing guide to constellations, planets, cosmic events and more)
HubbleSite - News Center (a complete collection of every Hubble Space Telescope news release)
HubbleSite - News Release Archive
HubbleSite - Index of Press Releases: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015.
Hubblesite - The James Webb Space Telescope (NASA's next orbiting observatory far beyond Earth's moon, Webb will detect infrared radiation)
HubbleSOURCE (Informal Science Education Resources)

National Aeronautics and Space Administration (NASA):
National Aeronautics and Space Administration (NASA) (Aeronautics Research, NASA - Human Exploration and Operations, Science: Earth, our Sun and Solar System, and the Universe, Space Technology. Created in 1958)
Aeronomy of Ice in the Mesosphere (AIM) Satellite Mission (Launch Date: April 25, 2007. Mission to explore Polar Mesospheric Clouds (PMCs), also called noctilucent clouds, to find out why they form and why they are changing. NASA's Aeronomy of Ice in the Mesosphere spacecraft was delivered into orbit from a Pegasus XL rocket. AIM's three scientific instruments will study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere.)
Alpha Magnetic Spectrometer (AMS-02) (Particle detector. Mounted on the ISS - Launched on May 16, 2011)
Ames Research Center (Entry Systems, Supercomputing, Next Generation Air Transportation, Airborne Sciences, Low-cost Missions, Biology and Astrobiology, Exoplanets, Autonomy and Robotics, Lunar Science, Human Factors, Wind Tunnel Testing. California. Established on December 20, 1939)
Aqua Satellite Project Science (Collecting information about the Earth's water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Also measuring radiative energy fluxes, aerosols, vegetation cover on the land, phytoplankton and dissolved organic matter in the oceans, and air, land, and water temperatures. First member of the "A-Train" satellite constellation. Launched on May 4, 2002)
Armstrong Flight Research Center (Advancing technology and science through flight)
Ask the Space Scientist (Frequently Asked Questions about the Sun, the Earth and their various interactions. Dr. Sten Odenwald, Astronomer)
Asteroid and Comet Watch (Latest news on Comets, Asteroids and Near-Earth Objects)
Astrobiology (The study of the origin, evolution, distribution, and future of life in the universe)
 - NASA Astrobiology Institute (NAI) (with e-mail news delivery service)
Astrobiology Magazine (Exploring the Solar System and beyond. NASA-sponsored. Established in 2000)
Astromaterials Research and Exploration Science (ARES) (Research in Earth, Planetary, and Space Sciences, Curatorial Responsibility for all NASA-held Extraterrestrial Samples. Johnson Space Center (JSC). Created in 2005)
 - Astrobiology Biomarkers (JSC scientists from many disciplines are investigating the origin and evolution of life)
Astronomy Picture of the Day (Each day a different image or photograph of our fascinating universe, along with a brief explanation written by a professional astronomer)
Aura Atmospheric Chemistry Mission (Aura (Latin for breeze) obtains measurements of ozone, aerosols and key gases throughout the atmosphere. Aura flies in formation about 15 minutes behind Aqua in the "A-Train" satellite constellation. Launched on July 15, 2004)
Beyond Earth: Expanding Human Presence Into the Solar System (Exploration at NASA)
Brain Bites (Educational Videos. So You Always Wanted To Ask NASA ...)
Breakthrough Propulsion Physics (Research within the realm of physics instead of technology. Ended on October 1, 2008)
CALIPSO Mission (Collecting information about the distribution of aerosols around the globe. Part of the "A-Train" satellite constellation. Launched on April 28, 2006)
Cassini-Huygens: Close Encounter with Saturn (Launched in October 15, 1997, Cassini reached Saturn in July 1, 2004. Along the way, it went past Venus, Earth and Jupiter in "gravity assist" maneuvers to increase the speed of the spacecraft. On December 25, 2004, Cassini released the European-built Huygens probe toward Titan. On January 14, 2005, the 2.7-meter-diameter (8.9-foot) Huygens entered Titan's atmosphere, deployed its parachutes and began its scientific observations during a descent of up to two and a half hours through the dense atmosphere. It provided our first direct sampling of Titan's atmospheric chemistry and the first photographs of its hidden surface. Cassini's four-year long prime mission ended on July 1, 2008, and the first extended mission, called the Cassini Equinox Mission, in September 2010. Now, the healthy spacecraft is seeking to make exciting new discoveries in a second extended mission called the Cassini Solstice Mission, which goes through September 2017)
Ciencia@NASA (Historias sobre ciencia de la NASA en Castellano)
Clouds and Earth's Radiant Energy System (CERES) (Providing Earth Radiation Budget data. Part of NASA's Earth Observing System (EOS). The first CERES instrument was launched in December of 1997 aboard NASA's Tropical Rainfall Measurement Mission (TRMM), CERES instruments are now collecting observations on three separate satellite missions, including the EOS Terra and Aqua observatories and now also on the Suomi National Polar-orbiting Partnership (S-NPP) observatory)
CloudSat Mission (Collecting information about the vertical structure of clouds. Part of the "A-Train" satellite constellation. Launched on April 28, 2006)
Chandra X-Ray Observatory (Discovering the X-Ray universe. Exploded stars, dispersal of elements, black holes, separation of dark matter. Launched into orbit by Space Shuttle Columbia in July 23, 1999)
COBE Science Mission (Cosmic Background Explorer. Launch Date: November 18, 1989.
The purpose of the Cosmic Background Explorer mission was to take precise measurements of the diffuse radiation between 1 micrometer and 1 cm over the whole celestial sphere. The following quantities were measured: (1) the spectrum of the 3 K radiation over the range 100 micrometers to 1 cm; (2) the anisotropy of this radiation from 3 to 10 mm; and, (3) the spectrum and angular distribution of diffuse infrared background radiation at wavelengths from 1 to 300 micrometers) The operational orbit was dawn-dusk Sun-synchronous so that the Sun was always to the side and thus was shielded from the instruments. With this orbit and spin-axis orientation, the instruments performed a complete scan of the celestial sphere every six months. COBE was launched November 18, 1989. Instrument operations were terminated December 23, 1993. As of January 1994, engineering operations were to conclude that month, after which operation of the spacecraft was transferred to Wallops for use as a test satellite)
 - The 2006 Gruber Cosmology Prize was awarded to John Mather and the COBE team for their 'ground-breaking studies of the spectrum and spatial structure of the relic radiation from the Big Bang'.
 - Scientist John Mather, from the Goddard Space Flight Center, and George Smoot, at the University of California, Berkeley, shared the 2006 Nobel Prize in Physics for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation measured by COBE.
Cosmic Background Explorer (COBE) (To measure the diffuse infrared and microwave radiation from the early universe to the limits set by our astrophysical environment. COBE carried three instruments: DIRBE (the Diffuse InfraRed Experiment) to search for and measure the cosmic infrared background radiation, DMR (Differential Microwave Radiometers) to map the cosmic microwave background radiation precisely, and FIRAS (Far-InfaRed Absolute Spectrophotometer) to compare the spectrum of the cosmic microwave background radiation with that from a precise blackbody. Launched in November 18, 1989. Instrument operations were terminated December 23, 1993. Decomissioned in 1997)
Cosmicopia (Cosmic and Heliospheric Learning Center, Cosmic Rays Studies)
Dawn Mission (Ion Propulsion. To study the asteroid Vesta and dwarf planet Ceres. From September 27, 2007 to July 2015)
De Astrónomos a Astronaves (Astronomía, Mecánica Newtoniana, el Sol, y Vuelos Espaciales, Dr. David P. Stern. En Español. Last updated in June 21, 2002)
Deep Impact (Mission to impact Comet Tempel 1 in July 4 '05, flyby of Comet Hartley 2 in 2010, and observe Comet Garradd in 2012. Launched in January 12, 2005. Declared lost in September 2013)
Discovery Program (Planetary science explorations. Marshall Space Flight Center)
Distributed Information Services for Climate and Ocean Products and Visualizations for Earth Research (DISCOVER) (To provide highly accurate, multi-decadal geophysical products derived from satellite microwave sensors. Earth System Data Records, including Climate Data Records. A collaboration of Remote Sensing Systems (RSS), NASA Marshall Space Flight Center, and the University of Alabama in Huntsville (UAH). Beginning with early work on SeaSat in 1978)
Earth Observatory (To share with the public the images, stories, and discoveries about climate and the environment that emerge from NASA research)
Earth Observing System (EOS) (Coordinated polar-orbiting satellites designed to monitor and understand key components of the climate system and their interactions)
Earth Observing Mission 1 (EO-1) (Developed and validated instrument and spacecraft bus breakthrough technologies to ensure Landsat data continuity and to enable the development of future Earth imaging observatories. General and Extended Missions. Launched into a polar orbit on November 21, 2000, with a design life of 18 months)
Earth Science Office (Integrated scientific understanding of the Earth system. Marshall Space Flight Center)
EPOXI Mission (Supplemental mission of NASA's Deep Impact spacecraft. Flyby of Comet Hartley 2 in November 4, 2010)
Fermi Gamma-ray Space Telescope (Formerly GLAST. Gamma rays are the highest-energy form of light, and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. The Large Area Telescope (LAT), the mission's main instrument, scans the entire sky every three hours. Fermi's secondary instrument, the Gamma-ray Burst Monitor (GBM), sees all of the sky at any instant, except the portion blocked by Earth. Launched in June 11, 2008)
 - NASA's Fermi Celebrates Five Years in Space, Enters Extended Mission (in August 11, 2013, ending in 2018)
Fourth Convection And Moisture EXperiment (CAMEX-4) (Marshall Space Center study of tropical cyclone (hurricane) development, tracking, intensification, structure, dynamics, motion and landfalling impacts using NASA-funded aircraft and surface remote sensing instrumentation. Out of Jacksonville within a 1,500 nm radius of the Naval Air Station, in Florida. Held in August 16 to September 24, 2001)
 - The Keys Area Microphysics Project (KAMP) made separate 300 nm flights from the air station near Key West Florida, to study thunderstorm structure, precipitation systems, and atmospheric water vapor profiles.
From Stargazers to Starships (Astronomy, Newtonian mechanics, the Sun, and Spaceflight. Dr. David P. Stern. Last updated in February 25, 2012)
Gamma Ray Astrophysics at the NSSTC (National Space, Science, and Technology Center (NSSTC). Projects designed to investigate the high energy regime of our Solar System and Universe. GLAST Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope). Entered Extended Mission in August 21, 2013. Launched in June 11, 2008)
Global Hydrology Resource Center (GHRC) (Provides both historical and current Earth science data, information, and products from satellite, airborne, and surface-based instruments. Managed by the Marshall Space Flight Center's Earth Science Department and the University of Alabama in Huntsville's Information Technology & Systems Center)
 - Lightning and Atmospheric Electricity Research (To determine the relationship between the electrical characteristics of storms and precipitation, convection, and severe weather)
 - Tropical storm tracks database (Storm information, including location, category, and wind speed)
Goddard Institute for Space Studies (GISS)
Goddard Space Flight Center (GSFC) (To build spacecraft, instruments and new technology to study the Earth, the Sun, our Solar System and the Universe. Established on May 1, 1959)
Gravity Probe B: The Relativity Mission (Used four ultra-precise gyroscopes to confirm two key predictions derived from Albert Einstein's general theory of relativity: The geodetic effect; the warping of space and time around a gravitational body (the Earth). And frame-dragging; the amount a spinning object (the Earth) pulls space and time with it as it rotates. Data collection started in August 28, 2004, and ended in August 14, 2005, 5 years of data analysis concluded in May 4, 2011. Resulsts published in Physical Review Letters (PRL) in May 31, 2011. Launched in April 20, 2004)
Gravity Recovery and Interior Laboratory (GRAIL) (Twin spacecraft, lauched in similar but separate trajectories to the Moon. GRAIL-A reached the Moon on New Year's Eve 2011. GRAIL-B arrived on New Year's Day 2012. The two solar-powered spacecraft flew in tandem near-circular, near-polar orbits around the Moon to measure its gravity field. For the next 82 days during the science phase, the spacecraft mapped the Moon's gravitational field. Now using that information to increase understanding of the Moon's interior and thermal history. On Dec. 17, 2012, GRAIL A and B were intentionally crashed into a mountain near the moon's north pole, as witnessed by NASA's Lunar Reconnaissance Orbiter (LRO). The Lyman Alpha Mapping Project (LAMP), an ultraviolet imaging spectrograph on board the LRO spacecraft, saw mercury and enhancements of atomic hydrogen in the impact plume. Launch Date: Sept. 10, 2011. Data collection from January 1, 2012 to March 23, 2012)
Headquarters Historical Reference Collection (Includes PDFs of Press Kits, Press Releases, Mission Transcripts, and Speeches)
Heliophysics Division (To understand the Sun and its interactions with the Earth and the solar system. A magnetic variable star, our Sun, drives the space environment of the planets, including the Earth. The earliest experiments discovered a link between the Sun and the Earth: Explorer 1 (1958, radiation belts), Mariner 2 (1962, solar wind) and Skylab (1973, coronal mass ejections and coronal holes as the source of solar wind). This led to the understanding that stars interact with the universe not just through gravity and photon radiation but also through electromagnetic fields and particles)
High Energy Astrophysics Science Archive Research Center (HEASARC) (Actual data from a multitude of space-based observatories. Archive for high-energy astronomy missions, observing at extreme ultraviolet, X-ray and gamma-ray wavelengths. Electromagnetic radiation from extremely energetic phenomena ranging from black holes to the Big Bang)
Hinode (SOLAR-B) Mission (Hinode, Japanese for "Sunrise" and formerly Solar-B, is a solar satellite mission developed, launched, and operated by the Institute of Space and Astronautical Science (ISAS) - a division of the Japanese Aerospace Exploration Agency (JAXA) - in collaboration with space agency partners from the National Astronomical Observatory of Japan (NAOJ), the United Kingdom, and the United States. Exploring the magnetic fields of the Sun. Hinode follows a sun-synchronous orbit over the day/night terminator at an altitude of more than 600 km. Launched from Uchinoura Space Center, Japan, on September 22, 2006)
History Division (Widely disseminating aerospace information and helping NASA managers to understand and learn from past successes and failures. The NASA History Program was first established in 1959)
 - Thinking About NASA History (History, History of Science and Technology, NASA History)
Hubble Space Telescope (Hubble is orbiting about 600 km (375 miles) above the surface of the Earth. Hubble's primary mirror is 2.4 meters (7 feet, 10.5 inches) across. There have been 5 servicing missions that continued to upgrade the telescope's scientific instruments and operational systems. The Hubble Space Telescope was deployed from the Space shuttle Discovery during STS-31 on April 25, 1990)
 - The Hubble Story (In 1983, the Space Telescope Science Institute (STScI) was established at The Johns Hopkins University in Baltimore, Maryland. The Space Telescope was renamed the Hubble Space Telescope (HST). By 1985, the telescope was assembled and ready for launch. In 1986 disaster struck. The Challenger accident forced NASA to ground the Space Shuttle fleet for two years. Finally, on April 24, 1990, the Space Shuttle Discovery lifted off from earth with the Hubble Space Telescope. The following day, Hubble was released into space, ready to peer into the vast unknown of space)
Human Space Flight (HSF) [NASA-TV, Shuttle, International Space Station (ISS), News and Features]
 - SkyWatch application (An Oracle Java Application to track satellite sightings)
 - The Apollo Program History (The Apollo program included a large number of uncrewed test missions and 11 crewed missions. The 11 crewed missions include two Earth orbiting missions, two lunar orbiting missions, a lunar swingby and six Moon landing missions. Lunar surface experiments included soil mechanics, meteoroids, seismic, heat flow, lunar ranging, magnetic fields and solar wind experiments. From October 11, 1968 to December 19, 1972)
Hurricanes/Tropical Cyclones (The Latest Storm Images and Data)
Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) (The first satellite mission dedicated to imaging the Earth's magnetosphere. Launched on March 25, 2000. On December 18, 2005, after 5.8 years of successful operations, IMAGE's telemetry signals were not received during a routine pass)
Intelligent Systems Division (Ames Reseach Center. Autonomous Systems and Robotics, Collaborative & Assistant Systems, Discovery and Systems Health, Robust Software Engineering)
International Space Station (ISS) (The ISS weighs approximately 419,573 Kg (925,000 pounds). The solar array wingspan is 73 meters (240 feet). The 75 to 90 kilowatts of power for the ISS is supplied by an acre of solar panels. The ISS measures 108.8 meters (357 feet) end-to-end. Zarya, the first ISS Module, was launched in November 20, 1998. In continuous human occupation since November 2, 2000)
International Year of Astronomy 2009 (A global celebration of astronomy and its contributions to society and culture, highlighted by the 400th anniversary of the first use of an astronomical telescope by Galileo Galilei. The aim is to stimulate worldwide interest, especially among young people, in astronomy and science under the central theme "The Universe, Yours to Discover.")
Interstellar Boundary Explorer (IBEX) (To map the boundary of the Solar System and discover the nature of the interactions at the boundary between the Solar wind and the interstellar medium. In orbit around Earth IBEX collects particles. These particles come from the boundary of the Solar System and beyond - from the interstellar medium. The Solar wind streams out into space and carves out a protective bubble around the Solar system called the heliosphere. IBEX has two sensors that collect particles called energetic neutral atoms (ENAs), traveling toward Earth from beyond the orbit of Pluto. An L-1011 airplane took a Pegasus rocket to high altitude. Then, the Pegasus rocket fired to propel it, and the IBEX spacecraft, into space. IBEX began its ride to space in October 19, 2008)
iSat: Interactive Satellite Viewer (NASA Science Javascript Satellite Tracking. The satellites are displayed based on their calculated positions in orbit)
James Webb Space Telescope (JWST) (Will be a large infrared telescope with a 6.5 meter primary mirror. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System. The project is working to a 2018 launch date)
Johnson Space Center (JSC) (Home to the NASA astronaut corps and is responsible for training space explorers from the United States and our space station partner nations. JSC serves as the lead NASA center for the International Space Station - a U.S.-led collaborative effort of 16 nations, and the largest, most powerful, complex human facility to ever operate in space. Houston, Texas)
J-Pass - Satellite Passes [Java] (A typical satellite in low Earth orbit (LEO) circles the Earth sixteen times each day, traveling 7.5 kilometers per second (27,000 km/hour). The best time to catch a glimpse of a satellite is either at dusk or at dawn, because satellites are most visible when they are in sunlight while the viewer is in darkness. Liftoff's Java program, called J-Pass, uses information provided by the North American Strategic Defense Command (NORAD) for more than a hundred bright satellites)
J-Track 3D - Satellite Tracking [Java]
Juno Mission (Juno's principal goal is to understand the origin and evolution of Jupiter. Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our solar system during its formation. As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars. Launched on August 5, 2011. Jupiter Orbit Insertion on July 5, 2016. End of mission on October 2017)
Kennedy Space Center (KSC) (By nature, human beings are explorers. For thousands of years, we've pushed beyond our boundaries, broadening our minds and imaginations with each new discovery. That same spirit of exploration is the driving force for Kennedy Space Center)
Kepler Mission (A mission capable of finding Earth-sized planets around other stars. The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. Launch Date: March 6, 2009. On a three and a half years mission)
 - Johannes Kepler (His Life, His Laws and Times: Johannes Kepler was born on December 27, 1571, in Weil der Stadt, Württemberg, in the Holy Roman Empire, of German Nationality. His evident intelligence earned him a scholarship to the University of Tübingen to study for the Lutheran ministry. There he was introduced to the ideas of Copernicus and delighted in them. In 1596, while a mathematics teacher in Graz, he wrote the first outspoken defense of the Copernican system, the Mysterium Cosmographicum. Kepler was forced to leave his teaching post at Graz due to the counter Reformation because he was Lutheran and moved to Prague to work with the renowned Danish astronomer, Tycho Brahe. He inherited Tycho's post as Imperial Mathematician when Tycho died in 1601. Using the precise data that Tycho had collected, Kepler discovered that the orbit of Mars was an ellipse. In 1609 he published Astronomia Nova, delineating his discoveries, which are now called Kepler's first two laws of planetary motion. In 1619 he published Harmonices Mundi, in which he describes his "third law". In spite of more forced relocations, Kepler published the Epitome Astronomiae in 1621. This was his most influential work and discussed all of heliocentric astronomy in a systematic way. He then went on to produce the Rudolphine Tables that Tycho had envisioned long ago. These included calculations using logarithms, which he developed, and provided perpetual tables for calculating planetary positions for any past or future date. Kepler used the tables to predict a pair of transits by Mercury and Venus of the Sun, although he did not live to witness the events)
La Exploracion de la Magnetosfera Terrestre (David P. Stern, Co-author Dr. Mauricio Peredo, en Español)
Una visión general de la investigación espacial sobre el entorno de la Tierra en el espacio.
Traducción al Español por J. Méndez. Última Actualización: Noviembre 9, 2004)
"La Tierra, el Gran Imán" - "Sobre el Magneto", de William Gilbert de Colchester
(400 Años desde "De Magnete". David P. Stern, en Castellano.
El año 2000 es un importante aniversario para la ciencia. Han pasado 400 años desde que "De Magnete" de William Gilbert apareció por vez primera, el primer estudio sistemático del magnetismo y de la electricidad. A Gilbert le debemos la noción (ahora sabida) de que la propiedad misteriosa de la aguja de la brújula de apuntar hacia el norte proviene del hecho de que la propia Tierra es un enorme imán. Gilbert también nos proporcionó el primer debate sobre la "fuerza electrick", enriqueciendo nuestro lenguaje y nuestras vidas con todas las cosas relativas a la electricidad, los electrones y la electrónica.
Pero lo mejor de todo, Gilbert introdujo con firmeza la idea de que el verdadero entendimiento de la naturaleza solo viene de los experimentos y las observaciones, no de postular como sería un mundo perfecto citando las opiniones sin base de los antiguos escritores.
Traducción al Español por J. Méndez. Última Actualización: Enero 31, 2003)
Landsat Science (Landsat Program Earth-observing satellites. The Landsat Program provides the longest continuous space-based record of Earth's land. Since the early 1970s, Landsat has continuously and consistently archived images of Earth)
Landsat Image Mosaic of Antarctica (LIMA) (The Landsat Image Mosaic of Antarctica (LIMA) is the first-ever true-color high-resolution satellite view of the Antarctic continent enabling everyone to see Antarctica as it appears in real life. LIMA was created from nearly 1,100 individual Landsat-7 images of Antarctica, most collected between 1999 and 2003.
This web page's content and links are no longer actively maintained. It is available for reference purposes only.)
LIDAR Applications Group (Langley Research Center. The group use Lidar technology on various aircraft to learn more about our atmosphere. Since 1991)
Lightning and Atmospheric Electricity at the GHCC (Global Hydrology and Climate Center. A group of researchers form the GHCC Lightning Team have been investigating the causes and effects of lightning as well as analyzing a wide variety of atmospheric measurements related to thunderstorms, to determine the relationship between the electrical characteristics of storms and precipitation, convection, and severe weather.
The Lightning Imaging Sensor (LIS), is a space based instrument used to detect the distribution and variability of total lightning (cloud-to-cloud, intracloud, and cloud-to-ground lightning) that occurs in the tropical regions of the globe. The LIS is a science instrument aboard the TRMM Observatory, which was launched on November 28, 1997, from the Tanegashima Space Center in Japan)
Lunar and Planetary Science at the NSSDC (The National Space Science Data Center (NSSDC) at Goddard Space Flight Center in Greenbelt, Maryland, is NASA's primary deep archive site for planetary and lunar data obtained from spacecraft missions, as well as the primary center for distribution of planetary data and images to educators and the general public)
Lunar Atmosphere and Dust Environment Explorer (LADEE) (A robotic spacecraft that had been orbiting the Moon since Oct. 6, 2013. On Nov. 10, 2013, LADEE began gathering science data, and on Nov. 20, 2013, the spacecraft entered its science orbit around the Moon's equator. LADEE had been in extended mission operations following a highly successful 100-day primary science phase. To impact on of the far side of the Moon's surface on or before April 21, 2014. Launched in September 6, 2013. Impacted the Moon on April 17, 2014)
Lunar Crater Observation and Sensing Satellite (LCROSS) (Oct. 21, 2010: The mission found evidence that the Lunar soil within shadowy craters is rich in useful materials, and the moon is chemically active and has a water cycle. LCROSS was launched with the Lunar Reconnaissance Orbiter (LRO) aboard an Atlas V rocket from Cape Canaveral, Fla., on June 18, 2009, and used the Centaur upper stage rocket to create the debris plume. The Lunar South Pole impact on October 9, 2009, indicated Water on the Moon)
Lunar Prospector (Launched on Jan. 6, 1998, Lunar Prospector mapped the Moon's surface composition and looked for possible deposits of polar ice, measure magnetic and gravity fields, as well as study lunar 'out gassing'. On March 5, 1998, scientists announced that Lunar Prospector's neutron spectrometer instrument had detected hydrogen at both Lunar poles, which scientists theorized to be in the form of water ice. Launched January 6, 1998, The mission ended on July 31, 1999, after scientists deliberately aimed Lunar Prospector to crash into a permanently shadowed area of a crater near the lunar South Pole. Researchers hoped that the impact would release water vapor from the suspected ice deposits and that the plume would be detectable from Earth, but no plume was observed)
Lunar Reconnaissance Orbiter (LRO) (Lauched in June 18, 2009, to begin the Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite missions to the Moon. Entered Lunar orbit June 23, 2009. Focused on supporting the extension of human presence in the Solar System, LRO helped identify sites close to potential resources with high scientific value, favorable terrain and the environment necessary for safe future robotic and human Lunar missions. LRO spent its first three years in a low polar orbit collecting detailed information about the Moon and its environment. After this initial orbit, LRO transitioned to a stable elliptical orbit, passing low over the Lunar south pole. And, after a year of exploration, was extended with a unique set of science objectives)
Madrid Deep Space Communications Complex (Complejo de Comunicaciones con el Espacio Profundo de Madrid, en Español. Este centro de comunicaciones se empezó a construir en 1.964, y su primera antena de 26 m de diámetro entró en funcionamiento al año siguiente. Desde entonces, y adaptándose a las necesidades de la Agencia Espacial de los Estados Unidos de Norteamérica, NASA, propietaria de las instalaciones, ha ido creciendo hasta la actualidad, con seis antenas de diferentes diámetros equipadas para el seguimiento de vehículos y sondas espaciales.
El complejo de Madrid forma parte de una red mundial que cuenta con otros dos centros similares en Australia y California. La situación geográfica de los mismos, separados aproximadamente 120 grados en longitud, ha sido elegida para que los vehículos puedan mantener contacto con alguna estación Terrena, independientemente del movimiento diario de rotación de la Tierra.
La red es conocida internacionalmente como DSN, siglas que corresponden a su nombre en Inglés: Deep Space Network (en Castellano Red del Espacio Profundo), y está dirigida y gestionada por el Jet Propulsion Laboratory (JPL) de Pasadena, California. En la actualidad constituye el sistema de telecomunicaciones para aplicaciones científicas mayor y más sensible del mundo)
Mariner Mars Missions (Mariner 4 was the first spacecraft to obtain and transmit close range images of Mars. After its launch on November 28, 1964 and a journey of hundreds of millions of kilometers, Mariner 4 passed within 9,844 kilometers of Mars on July 14, 1965. Data acquisition continued until December 20, 1967.
Mariner 6 and Mariner 7 were identical spacecraft launched on February 24, 1969 and March 27, 1969 respectively, and their missions were entirely devoted to the flyby study of Mars. The probes passed closest to Mars on July 30 and August 4 of the same year. The images essentially deflated any of the theories proposing the existence of artificial canals on the surface. Atmospheric experiments indicated the presence of dust suspended in the atmosphere, carbon dioxide ice and water ice clouds, carbon monoxide, ionized hydrogen, and ionized oxygen. Among the species not detected were ozone and nitrogen; both of which would have been beneficial to the existence of life similar to that on Earth. Surface temperatures as warm as 280-290K (290K is about 17° Celsius or 63° Fahrenheit) were detected near the equator, with atmospheric pressure between 3.8 to 7.0 millibars.
Originally, Mariner 9 was to have an identical companion, Mariner 8, but on May 8, 1971, 365 seconds after launch, Mariner 8's Centaur main engine shut down and the upper stage of the rocket, along with Mariner 8, fell into the Atlantic about 560 km north of Puerto Rico.
Mariner 9 was the first of NASA's Mars orbiters. Launched on May 30, 1971, Mariner 9 arrived in Mars orbit on November 14, 1971. By the end of 349 days in Mars orbit, 7,329 images (including images of Mars' two moons, Phobos and Deimos) had been relayed back to Earth. Upon its arrival the spacecraft was presented with a Martian atmosphere full of dust which obscured the view of the surface. The opaqueness, explained as dust storms of the Martian atmosphere, had been previously observed from Earth during Martian southern hemisphere summers and now with Mariner 9 in orbit, the existence of these dust stroms was confirmed. Mariner 9 was kept in orbit until the dust began to settle out of the atmosphere and the systematic imaging of the planet's surface began in January of 1972. The 7,329 images, covering about 80% of the planet, revealed the surface and atmosphere of Mars to be as varied as planetary scientists had hoped. Some of the observed features included ancient river beds, craters, massive extinct volcanoes, canyons, layered polar deposits, evidence of wind-driven deposition and erosion of sediments, weather fronts, ice clouds, localized dust storms, morning fogs and more. With evidence of flow features, and therefore the possibilty of a time when water was in liquid form on the surface of Mars, the question of the existence of life on Mars was intensified.
The information from this mission would later serve as the foundation for the Viking program)
Mars Atmosphere and Volatile Evolution Mission (MAVEN) (Launched in November 18, 2013, and is on track to arrive at Mars on September 21, 2014. A mission to explore the Red Planet's upper atmosphere, ionosphere and interactions with the Sun and Solar wind. Understanding atmospheric loss will give scientists insight into the history of Mars' atmosphere and climate, liquid water, and planetary habitability)
Mars Exploration Program Landing Sites (Marsoweb interactive data maps. Java)
Mars Exploration Rovers (Spirit & Opportunity: Finding the Water and Conditions for Life. Ten years of discovery on Mars. The rovers tell us of an ancient time when Mars was awash in water, with good conditions for supporting microbial life.)
Mars Reconnaissance Orbiter (MRO) (Launched August 12, 2005. On a search for evidence that water persisted on the surface of Mars for a long period of time. While other Mars missions have shown that water flowed across the surface in Mars' history, it remains a mystery whether water was ever around long enough to provide a habitat for life. The orbiter's primary mission ended about five and a half years after launch, on December 31, 2010)
Mars Science Laboratory, the Next Mars Rover (Launched November 26, 2011, Arrived August 6, 2012. Rover Curiosity)
Marshall Space Flight Center (The Marshall team is leading development of NASA's Space Launch System, or SLS, the next advanced, heavy-lift launch vehicle)
MESSENGER Mission (Mercury Surface, Space Environment, Geochemistry and Ranging Mission. Launched in August 3, 2004. Earth flyby, August 2005. Venus flyby, October 2006. 2nd Venus flyby, June 2007. Mercury flyby, January 2008. 2nd Mercury flyby, October 2008. 3rd Mercury flyby, September 2009. A Year-long science orbit of Mercury began in March 18, 2011. The primary mission was completed on March 17, 2012. MESSENGER achieved 100% mapping of Mercury on March 6, 2013. On March 17, 2013, MESSENGER successfully completed its year-long first extended mission in orbit about Mercury. Its second extended mission concluded on April 30, 2015)
Mini-RF (The Mini-RF project launched in June 2009 two radar instruments to the Moon to map the Lunar poles, search for water ice, and to demonstrate future NASA communication technologies. The first instrument, launched on the Indian Space Research Organisation's (ISRO) Chandrayaan-1 spacecraft, concentrated on mapping both polar regions. The second instrument is currently flying on NASA's Lunar Reconnaissance Orbiter (LRO) and has been mapping the different geologic units of the Lunar surface. LRO is carrying seven instruments and is currently mapping the Moon from a 50-kilometer circular polar orbit.
Chandrayaan-1 was India's first mission to the Moon. It consisted of an orbiter that mapped the Moon, initially from a 100-kilometer circular polar orbit. It carried 11 instruments, including Mini-SAR. It launched in October 2008; the mission ended in August 2009)
Moderate Resolution Imaging Spectroradiometer (MODIS) (MODIS is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra's orbit around the Earth is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon. Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths)
NASA Earth Observations (NEO) (Imagery: Atmosphere, Energy, Land, Life, Ocean. One of the best places to study Earth is from space. NASA satellites continually orbit the globe, collecting information about Earth's ocean, atmosphere, and land surfaces. Satellites can even monitor the activity of life forms, such as phytoplankton, from their remote vantage points)
NASA Eclipse Web Site (Solar and Lunar Eclipse Information. Eclipses of the Sun. Eclipses of the Moon, Planetary Transits Across the Sun, Solar System Data)
NASA Education (NASA's journeys into air and space have deepened humankind's understanding of the universe, advanced technology breakthroughs, enhanced air travel safety and security, and expanded the frontiers of scientific research. These accomplishments share a common genesis: education)
NASA en Español (Más de una Década Informando en Español)
NASA/IPAC Extragalactic Database (NED) (NED is a comprehensive database of multiwavelength data for extragalactic objects, providing a systematic, ongoing fusion of information integrated from hundreds of large sky surveys and tens of thousands of research publications. The contents and services span the entire observed spectrum from gamma rays through radio frequencies. NED contains names, positions, and a variety of other data for extragalactic objects, as well as bibliographic references to published papers, and notes from catalogs and other publications. NED serves a variety of data, including images and spectra at all wavelengths)
NASA Learning Technologies (NLT) (NASA's educational-technology incubator)
NASA Missions (Alphabetical List of Missions, Browse Missions by Topic. Launch Schedule: the planned dates and details for missions by NASA, commercial companies and the partner nations in the International Space Station Program, including Russia, European Space Agency and Japan)
NASA Multimedia (Images, videos and interactive media)
NASA Quest (Interactive explorations, an educational Website. NASA Quest Challenges are Web-based, interactive explorations designed to engage students in authentic scientific and engineering processes)
NASA Science (Earth, Heliophysics, Planets, Astrophysics. Seeking new knowledge and understanding of our planet Earth, our Sun and solar system, and the universe out to its farthest reaches and back to its earliest moments of existence)
National Space Science Data Center (NSSDC) (The National Space Science Data Center serves as the permanent archive for NASA space science mission data. "Space science" means astronomy and astrophysics, solar and space plasma physics, and planetary and lunar science)
 - NSSDC Photo Gallery
 - NSSDC Planetary Catalog of Spaceborne Imaging
Near-Earth Object Program (Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighborhood. Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter. The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged remnant debris from the solar system formation process some 4.6 billion years ago. The giant outer planets (Jupiter, Saturn, Uranus, and Neptune) formed from an agglomeration of billions of comets and the left over bits and pieces from this formation process are the comets we see today. Likewise, today's asteroids are the bits and pieces left over from the initial agglomeration of the inner planets that include Mercury, Venus, Earth, and Mars.
As the primitive, leftover building blocks of the solar system formation process, comets and asteroids offer clues to the chemical mixture from which the planets formed. If we wish to know the composition of the primordial mixture from which the planets formed, then we must determine the chemical constituents of the leftover debris from this formation process - the comets and asteroids)
New Horizons Mission (To Pluto and Charon - Kuiper Belt Objects. The first reconnaissance of Pluto and Charon - a "double planet" and the last planet in our solar system to be visited by spacecraft. Later, as part of an extended mission to 2020, New Horizons will visit one or more objects in the Kuiper Belt region beyond Neptune.
Launched on January 19, 2006. Jupiter Encounter: Closest approach occurred on February 28, 2007. New Horizons flew about 3 to 4 times closer to Jupiter than the Cassini spacecraft. New Horizons has also crossed the orbits of Saturn, on June 8, 2008, Uranus on March 18, 2011, and Neptune on August 2014. It transitioned from hibernation to active mode on Dec. 6, 2014, in preparation for the Pluto-System Encounter close approach on July 14, 2015 (11:49:59 UTC). See New Horizons - The Flyby)
Nuclear Spectroscopic Telescope Array (NuSTAR) Mission (The NuSTAR mission has deployed the first orbiting telescopes to focus light in the high energy X-ray (6 - 79 keV) region of the electromagnetic spectrum. Our view of the universe in this spectral window has been limited because previous orbiting telescopes have not employed true focusing optics, but rather have used coded apertures that have intrinsically high backgrounds and limited sensitivity. Launched on June 13, 2012.)
Phoenix Mars Lander Mission (Mission to locate underground water. Launched on August 4, 2007, Phoenix landed on Mars on May 25, 2008, farther north than any previous spacecraft sent to Mars. The lander dug, scooped, baked, sniffed and tasted the Red Planet's soil just below ground level. Among early results, it verified the presence of water-ice in the Martian subsurface, which NASA's Mars Odyssey orbiter in 2002 first detected remotely in large amounts in the northern arctic plain. The Phoenix lander targets this circumpolar region using a robotic arm to dig through the protective top soil layer to the water ice below and ultimately, to bring both soil and water ice to the lander platform for sophisticated scientific analysis. In May 24, 2010, NASA's Phoenix Mars Lander has ended operations after repeated attempts to contact the spacecraft were unsuccessful. A new image transmitted by NASA's Mars Reconnaissance Orbiter shows signs of severe ice damage to the lander's solar panels. Phoenix was not designed to survive the dark, cold, icy Martian winter. It was anticipated that the weight of a carbon-dioxide ice buildup could bend or break the lander's solar panels. The mission's biggest surprise was the discovery of perchlorate, an oxidizing chemical on Earth that is food for some microbes and potentially toxic for others. The perchlorate results are shaping subsequent astrobiology research, as scientists investigate the implications of its antifreeze properties and potential use as an energy source by microbes)
Pioneer Mission (The Pioneer Spacecraft Missions are a series of eight spacecraft missions managed by the Pioneer Project Office at NASA, Ames Research Center.
Pioneer I launched 54 years ago on October 11, 1958, the first spacecraft launched by the 11-day-old National Aeronautics and Space Administration (NASA). Although the spacecraft failed to reach the Moon, it did transmit 43 hours of data.
Pioneers 6-9 were launched into Solar orbit between 1965 and 1968. Their prime mission completed years ago, the spacecraft were then tracked only occasionally.
Launched on March 2, 1972, Pioneer 10 was the first spacecraft to travel through the Asteroid belt, and the first spacecraft to make direct observations and obtain close-up images of Jupiter. The end of its science mission was on March 31, 1997. After more than 30 years, it appears the venerable Pioneer 10 spacecraft has sent its last signal to Earth. Pioneer's last, very weak signal was received on January 23, 2003. NASA engineers report that Pioneer 10's radioisotope power source has decayed, and it may not have enough power to send additional transmissions to Earth. NASA's Deep Space Network (DSN) did not detect a signal during a contact attempt on February 7, 2003. The previous three contacts, including the January 23 signal, were very faint, with no telemetry received. The last time a Pioneer 10 contact returned telemetry data was April 27, 2002.
The extended mission for Pioneer 10 was to search for the heliopause. The heliopause is the meeting surface of the Solar wind and the medium outside the Solar environment where the region of interstellar space begins. The Pioneer scientists now predict the distance from the Sun at which the terminal shock may be encountered is from 60 to 100 astronomical units (AU) or more.
Along with its sister ship Pioneer 11, Pioneer 10 carries a plaque with messages designed to make contact with possible alien civilizations. The late Dr. Carl Sagan helped devise the plaques that bear the illustration of a man and a woman as well as a diagram identifying earth's location in the galaxy.
The Pioneer 11 spacecraft launched from Cape Canaveral forty years ago, on April 5, 1973. Pioneer 11's path through Saturn's outer rings took it within 21,000 km of the planet, where it discovered two new moons (almost smacking into one of them in September 1979) and a new "F" ring. The spacecraft also discovered and charted the magnetosphere, magnetic field and mapped the general structure of Saturn's interior. The spacecraft's instruments measured the heat radiation from Saturn's interior and found that its planet-sized moon, Titan, was too cold to support life. The Pioneer 11 Mission ended on September 30, 1995, when the last transmission from the spacecraft was received.
Pioneer Venus Orbiter (Pioneer 12) was launched on May 20, 1978. On December 4, 1978, the orbiter was injected into a highly elliptical orbit around Venus. The periapsis, or low orbital point, of the orbit was about 150 km (93 miles) above the surface of the planet. During the Orbiter's mission, opportunities arose to make systematic observations of several comets with the Ultraviolet Spectrometer (OUVS). On October 8, 1992, its fuel supply exhausted, the Orbiter ended its mission as a meteor flaming through the dense atmosphere of Venus)
Planck Space Telescope (Exploring the Birth of Our Universe. Planck is a European Space Agency mission with significant participation from NASA. It was launched into space from French Guiana in May 14, 2009, and now orbits a distant point, called the second Lagrange point [L2] of our Earth-Sun system, about 1.5 million kilometers (930,000 miles) away.
Planck will give us the best view yet of the early moments of cosmic history - moments that are responsible for all we see around us today. It will make the most precise measurements to date of tiny variations in the universe's oldest light, called the cosmic microwave background, created more than 13 billion years ago. The mission will refine our estimates of the size, mass, age, composition, geometry and fate of the universe - whether it will collapse in on itself, or expand forever. The team will produce a catalogue of cosmic objects, called the Early Release Compact Source Catalogue, which will be released to the public nine months after completion of the first sky survey)
 - Planck Mission Brings Universe Into Sharp Focus (March 21 2013: The Planck space mission has released the most accurate and detailed map ever made of the oldest light in the universe, revealing new information about its age, contents and origins. The map results suggest the universe is expanding more slowly than scientists thought, and is 13.8 billion years old, 100 million years older than previous estimates. The data also show there is less dark energy and more matter, both normal and dark matter, in the universe than previously known. Dark matter is an invisible substance that can only be seen through the effects of its gravity, while dark energy is pushing our universe apart. The nature of both remains mysterious.
The map, based on the mission's first 15.5 months of all-sky observations, reveals tiny temperature fluctuations in the cosmic microwave background, ancient light that has traveled for billions of years from the very early universe to reach us. The patterns of light represent the seeds of galaxies and clusters of galaxies we see around us today.
The age, contents and other fundamental traits of our universe are described in a simple model developed by scientists, called the standard model of cosmology. These new data have allowed scientists to test and improve the accuracy of this model with the greatest precision yet. At the same time, some curious features are observed that don't quite fit with the simple picture. For example, the model assumes the sky is the same everywhere, but the light patterns are asymmetrical on two halves of the sky, and there is a spot extending over a patch of sky that is larger than expected.
The findings also test theories describing inflation, a dramatic expansion of the universe that occurred immediately after its birth. In far less time than it takes to blink an eye, the universe blew up by 100 trillion trillion times in size. The new map, by showing that matter seems to be distributed randomly, suggests that random processes were at play in the very early universe on minute "quantum" scales. This allows scientists to rule out many complex inflation theories in favor of simple ones.
Planck launched in 2009 and has been scanning the skies ever since, mapping the cosmic microwave background, the afterglow of the theorized big bang that created our universe. This relic radiation provides scientists with a snapshot of the universe 370,000 years after the big bang. Light existed before this time, but it was locked in a hot plasma similar to a candle flame, which later cooled and set the light free.
The cosmic microwave background is remarkably uniform over the entire sky, but tiny variations reveal the imprints of sound waves triggered by quantum fluctuations in the universe just moments after it was born. These imprints, appearing as splotches in the Planck map, are the seeds from which matter grew, forming stars and galaxies. Prior balloon-based and space missions learned a great deal by studying these patterns, including NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and the Cosmic Background Explorer (COBE), which earned the COBE Team the 2006 Nobel Prize in Physics.
The newly estimated expansion rate of the universe, known as Hubble's constant, is 67.15 plus or minus 1.2 kilometers/second/megaparsec. A megaparsec is roughly 3 million light-years. This is less than prior estimates derived from space telescopes, such as NASA's Spitzer and Hubble, using a different technique. The new estimate of dark matter content in the universe is 26.8 percent, up from 24 percent, while dark energy falls to 68.3 percent, down from 71.4 percent. Normal matter now is 4.9 percent, up from 4.6 percent)
Planetary Laser Altimetry (A laser altimeter is an instrument that measures the distance from an orbiting spacecraft to the surface of the planet/asteroid that the spacecraft is orbiting. The distance is determined by measuring the complete round trip time of a laser pulse from the instrument to the planet's/asteroid's surface and back to the instrument. The distance to the object can be determined by multiplying the round-trip pulse time by the speed of light and dividing by two. With a well-known attitude and position of the instrument/spacecraft the location on the surface illuminated by the laser pulse can be determined. The series of the laser spot, or footprint, locations provides a profile of the surface)
Polar, Wind, and Geotail Missions (In the 1990s, collaborations between NASA, the European Space Agency (ESA), and the Institute of Space and Astronuatical Science (ISAS) of Japan resulted in the International Solar-Terrestrial Physics (ISTP) Science Initiative. Polar, Wind and Geotail are a part of this initiative, combining resources and scientific communities to obtain coordinated, simultaneous investigations of the Sun-Earth space environment over an extended period of time)
 - Polar Project (The Polar satellite, launched on February 24, 1996, is in a highly elliptical, 86 deg inclination orbit with a period of about 17.5 hours. Within the Sun-Earth Connections fleet, Polar has the responsibility for multi-wavelength imaging of the aurora, measuring the entry of plasma into the polar magentosphere and the geomagnetic tail, the flow of plasma to and from the ionosphere, and the deposition of particle energy in the ionosphere and upper atmosphere. Polar was launched to observe the polar magnetosphere and, as its orbit has precessed with time, has observed the equatorial inner magnetosphere and is now progressing toward an extended southern hemisphere campaign)
 - Wind Spacecraft (Wind was launched on November 1, 1994 and is the first of two NASA spacecraft in the Global Geospace Science initiative and part of the ISTP Project)
 - Geotail Project (The GEOTAIL mission is a collaborative project undertaken by the Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), and the National Aeronautics and Space Administration (NASA). The Geotail spacecraft was designed and built by ISAS and was launched on July 24, 1992. After fulfilling Its original objective of studying the dynamics of the Earth's magnetotail over a wide range of distance, extending from the near-Earth region (8 Earth radii (Re) from the Earth) to the distant tail (about 200 Re) its orbit was changed. Since February 1995 Geotail has been in an elliptical 9 by 30 Re orbit where it has provided data on most aspects of the solar wind interaction with the magnetosphere)
Precipitation Measurement Missions (An international partnership to understand precipitation and its impact on humankind)
 - Global Precipitation Measurement (GPM) mission (An international network of satellites that provide the next-generation global observations of rain and snow)
 - Tropical Rainfall Measuring Mission (TRMM) (Since its launch in 1997, TRMM has provided critical precipitation measurements in the tropical and subtropical regions of our planet. The Precipitation Radar (PR) can see through the precipitation column, providing new insights into tropical storm structure and intensification. The TRMM Microwave Imager (TMI) measures microwave energy emitted by the Earth and its atmosphere to quantify the water vapor, the cloud water, and the rainfall intensity in the atmosphere. TRMM precipitation measurements have made and continue to provide critical inputs to tropical cyclone forecasting, numerical weather prediction, and precipitation climatologies)
 - Weather & Climate | Precipitation Education (Rain, snow, and other forms of precipitation affect every part of life on Earth. Rain falls on the crops we eat, fills the reservoirs of water we drink, and is an integral part of everyday weather and long term climate trends)
Radioisotope Power Systems (For more than five decades, radioisotope power systems have played a critical role in the exploration of space, enabling missions of scientific discovery to destinations across the solar system. There are currently only two practical options for providing a long-term source of electrical power for exploring space: the light of the Sun or heat from a nuclear source such as a radioisotope. Solar power is an excellent way to generate electricity for most Earth-orbiting spacecraft, and for certain missions to the Moon and places beyond that offer sufficient sunlight and natural heat. However, many potential NASA missions given a high priority by the scientific community would visit some of the harshest, darkest, coldest locations in the solar system, and these missions could be impossible or extremely limited without the use of nuclear power. Radioisotope power systems - abbreviated RPS - are a type of nuclear energy technology that uses heat to produce electric power for operating spacecraft systems and science instruments. That heat is produced by the natural radioactive decay of plutonium-238. RPS offer several important benefits. They are compact, rugged and provide reliable power in harsh environments where solar arrays are not practical. For example, Saturn is about ten times farther from the sun than Earth, and the available sunlight there is only one hundredth, or one percent, of what we receive at Earth. At Pluto, the available sunlight is only six hundredths of a percent of the amount available at Earth. The ability to utilize radioisotope power is important for missions to these and other incredibly distant destinations, as the size of Solar arrays required at such distances is impractically large with current technology)
Radio JOVE Project (Amateur Jupiter Radio-Astronomy. Radio JOVE students and amateur scientists observe and analyze natural radio emissions of Jupiter, the Sun, and our galaxy)
Rapid Response | EOSDIS (The Earth Observing System Data and Information System (EOSDIS) is a key core capability in NASA's Earth Science Data Systems Program. It provides end-to-end capabilities for managing NASA's Earth science data from various sources - satellites, aircraft, field measurements, and various other programs. For the EOS satellite missions, EOSDIS provides capabilities for command and control, scheduling, data capture and initial (Level 0) processing)
 - NASA Worldview (Interactively browse MODIS data and global, full-resolution satellite imagery from either the Aqua or Terra polar-orbiting satellites)
Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) (To explore the basic physics of particle acceleration and energy release in solar flares. Simultaneous, high resolution imaging and spectroscopy of solar flares from 3 keV X-rays to 17 MeV gamma rays with high time resolution. In circular Earth orbit, 600 km (373 miles), 38 degree inclination. Field of View: Full Sun (1 degree). Spacecraft Pointing: Spin stabilized at 15 rpm, Sun-center pointing to 0.2 degrees. Launched in February 5, 2002)
SAO/NASA Astrophysics Data System (ADS) (Harvard-Smithsonian/NASA Digital Library for Physics and Astronomy. The ADS maintains three bibliographic databases containing more than 11.0 million records covering publications in Astronomy and Astrophysics, Physics, and the arXiv e-prints. Abstracts and full-text of major astronomy and physics publications are indexed and searchable)
Science@NASA Headline News (Author | Production editor: Dr. Tony Phillips)
 - Ciencia@NASA (Historias sobre ciencia de la NASA en Castellano)
Scientific Visualization Studio (SVS) (The SVS works closely with scientists in the creation of visualizations, animations, and images in order to promote a greater understanding of Earth and Space Science)
Shuttle Online Press Kits (Shuttle mission information. Johnson Space Center)
SkyView (The Internet's Virtual Telescope. SkyView is a Virtual Observatory on the Net generating images of any part of the sky at wavelengths in all regimes from Radio to Gamma-Ray)
Solar and Heliographic Observatory (SOHO) (SOHO, the Solar & Heliospheric Observatory, is a project of international collaboration between ESA and NASA to study the Sun from its deep core to the outer corona and the Solar wind. SOHO moves around the Sun in step with the Earth, by slowly orbiting around the First Lagrangian Point (L1), where the combined gravity of the Earth and Sun keep SOHO in an orbit locked to the Earth-Sun line. The L1 point is approximately 1.5 million kilometers away from Earth (about four times the distance of the Moon), in the direction of the Sun. There, SOHO enjoys an uninterrupted view of our daylight star. SOHO was launched on December 2, 1995)
Solar Data Analysis Center (SDAC) (The Solar Data Analysis Center serves data from recent and current space-based solar-physics missions, funds and hosts much of the SolarSoft library, and leads the Virtual Solar Observatory (VSO) effort)
Solar Dynamics Observatory (SDO) (The Solar Dynamics Observatory (SDO) will be taking a closer look at the Sun, the source of all Space Weather. Many satellites share a ground system (place on the ground where they send data and photographs) and have recording systems to save the data collected until they can talk to their ground station. Because SDO has no recording system and will be collecting so much data, the SDO mission has to build its very own ground station. For this to be possible, SDO has to be placed in a geosynchronous orbit (GEO). This means that it will rotate at the same speed as the Earth and will always be directly above and in constant communication with its ground station in New Mexico. Launched in February 11, 2010)
Solar Physics (The Solar Physics Group at NASA's Marshall Space Flight Center was formed in the early 1970's in conjunction with the Apollo Skylab Mission. These pages contain an overview of solar physics itself along with highlights of our own work, our current projects, and possible future missions. Marshall Space Flight Center)
Solar Probe Plus (Solar Probe Plus will be an extraordinary and historic mission, exploring what is arguably the last region of the solar system to be visited by a spacecraft, the Sun's outer atmosphere or corona as it extends out into space. Solar Probe Plus will repeatedly sample the near-Sun environment, revolutionizing our knowledge and understanding of coronal heating and of the origin and evolution of the solar wind and answering critical questions in heliophysics that have been ranked as top priorities for decades. Moreover, by making direct, in-situ measurements of the region where some of the most hazardous solar energetic particles are energized, Solar Probe Plus will make a fundamental contribution to our ability to characterize and forecast the radiation environment in which future space explorers will work and live. For launch in July 30, 2018. First Close Solar Approach in December 19, 2024)
Solar System Exploration (This site provides content on missions, events, education, people and other things related to the exploration of the planets in our solar system. We strive to be a living encyclopedia of NASA's robotic exploration of our solar system updated in near real time. We are not a source for breaking news. We archive news releases and other articles to preserve a historical record of solar system exploration)
 - Deep Space 1 (DS1) (Ion Propulsion and Advanced Technologies Demonstrator. Launched on October 24, 1998, encounter with Comet Borrelly in September 22, 2001, mission ended on December 18, 2001.
Deep Space 1 was an engineering test flight for a dozen new technologies, including highly-efficient ion engines and autonomous navigation software. Asteroid 9969 Braille flyby on July 29, 1999, was a bonus science target.
 - Galileo Legacy Site (Jupiter Mission, launched in October 18, 1989, from the cargo bay of the Space Shuttle Atlantis. The spacecraft was named in honor of the first modern astronomer - Galileo Galilei. He made the first observations of the heavens using a telescope in 1610.
The Galileo spacecraft didn't have enough fuel to fly directly to Jupiter, but it could borrow enough energy from Venus and Earth to make the long journey. Mission planners designed a flight path nicknamed "VEEGA" - Venus-Earth-Earth Gravity Assist. Galileo would slingshot once by Venus, and twice by Earth, gathering enough momentum to reach distant Jupiter. Flying by our home planet twice, Galileo saw the Earth and Moon together - as someone from another world might view us. On Galileo's first trip through the asteroid belt, the spacecraft took detailed images of an asteroid named Gaspra in November 29, 1991 - the first close approach to an asteroid. On a second pass through the asteroid belt, Galileo discovered a miniature moon orbiting asteroid Ida in August 28, 1993. This tiny body was named Dactyl. In 1994, Galileo was perfectly positioned to watch the fragments of comet Shoemaker-Levy 9 crash into Jupiter. The spacecraft made the only direct observations of the impact. Galileo arrived at Jupiter in December 1995.
In July 1995, the probe was released to begin a solo flight into Jupiter. Five months later, in December 7, 1995, the probe sliced into Jupiter's atmosphere at one-hundred-six-thousand miles per hour. It slowed, released its parachute, and dropped its heat shield. As the probe descended through ninety-five miles of the top layers of the atmosphere, it collected fifty-eight minutes of data on the local weather. The data were sent to the spacecraft overhead, then transmitted back to Earth. Towards the end of the 58 minute descent, the probe measured winds of four-hundred-and-fifty miles per hour - stronger than anything on Earth. The probe was finally melted and vaporized by the intense heat of the atmosphere. Galileo was the first to measure Jupiter's atmosphere with a descent probe and the first to conduct long-term observations of the Jovian system from Jupiter's orbit. It found evidence of subsurface saltwater on Europa, Ganymede and Callisto and revealed the intensity of volcanic activity on Io.
Galileo changed the way we look at our Solar System. The spacecraft was the first to fly past an asteroid and the first to discover a moon of an asteroid. It provided the only direct observations of a comet colliding with a planet. Galileo plunged into Jupiter's crushing atmosphere on September 21, 2003)
Solar TErrestrial RElations Observatory (STEREO) (Launched in October 25, 2006. STEREO is the third mission in NASA's Solar Terrestrial Probes program (STP). It employs two nearly identical space-based observatories - one Ahead of Earth in its orbit, the other trailing Behind - to provide the first-ever stereoscopic measurements to study the Sun and the nature of its coronal mass ejections, or CMEs. With this new pair of viewpoints, scientists will be able to see the structure and evolution of Solar storms as they blast from the Sun and move out through space)
Suomi National Polar-orbiting Partnership (NPP) (Launched in October 28, 2011. Over the last dozen years, NASA has launched a series of satellites - known collectively as the Earth Observing System (EOS) - that has provided critical insights into the dynamics of the entire Earth system: clouds, oceans, vegetation, ice, solid Earth and atmosphere. Now NASA is helping to create a new generation of satellites to extend and improve upon the Earth system data records established by EOS. Suomi National Polar-orbiting Partnership, formerly known as the NPOESS Preparatory Project, will serve as a bridge between the EOS satellites and the forthcoming series of Joint Polar Satellite System (JPSS) satellites)
 - Earth at Night (December 5, 2012: NASA-NOAA Satellite Reveals New Views of Earth at Night. This new global view and animation of Earth's city lights is a composite assembled from data acquired by the Suomi NPP satellite. The data was acquired over nine days in April 2012 and 13 days in October 2012)
Space Place (Science, technology and learning about space for elementary school kids)
Space Place (Ciencia, tecnología y aprendizaje sobre el espacio para escolares. En Español)
SpaceWeather.com (Science news and information about the Sun-Earth environment, Global satellite tracking)
Spitzer Space Telescope (Launched on August 25, 2003. The Spitzer Space Telescope is the final mission in NASA's Great Observatories Program - a family of four space-based observatories, each observing the Universe in a different kind of light. The other missions in the program include the visible-light Hubble Space Telescope (HST), Compton Gamma-Ray Observatory (CGRO), and the Chandra X-Ray Observatory (CXO). Drifting in a unique Earth-trailing orbit around the Sun, Spitzer sees an optically invisible universe dominated by dust and stars. Spitzer is designed to detect infrared radiation, which is primarily heat radiation. All of Spitzer's cold items are kept in the Cryogenic Telescope Assembly (CTA). A tank of liquid helium, called the "cryostat", acts as a coolant - producing a freezing vapor that cools the entire CTA to about five degrees Kelvin (-459 Fahrenheit, or -268 Celsius). Spitzer's telescope is a lightweight reflector of Ritchey-Chrétien design, with a mirror measuring 85 centimeters in diameter. It weighs less than 50 kg (110 pounds), and is designed to operate at an extremely low temperature. All of its parts, except for the mirror supports, are made of beryllium, which is extremely light but very strong)
Spitzer el Telescopio Espacial (El sitio en Español. El Telescopio Espacial Spitzer (antes denominado SIRTF, por sus siglas en Inglés), consiste en un observatorio espacial infrarrojo enfriado criogénicamente, capaz de estudiar objetos que van desde nuestro Sistema Solar hasta las regiones más distantes del Universo. En una órbita heliocéntrica, siguiendo a la Tierra, Spitzer es el elemento final del Programa de Grandes Observatorios de la NASA, y una pieza clave desde el punto de vista científico y técnico del nuevo Programa para la Búsqueda Astronómica de los Orígenes. Debido a que el Observatorio tiene que ser enfriado a unos pocos grados por encima del cero absoluto, esta órbita ofrece un ambiente térmico más benigno que cualquier órbita Terrestre. La Tierra no solo refleja luz visible procedente del Sol sino que también emite radiación infrarroja. Cualquier satélite en una órbita Terrestre razonable se encuentra rodeado de un medio con temperaturas mayores de 250 K. La órbita heliocéntrica pondrá a Spitzer en el espacio "profundo," donde la temperatura ambiente está entre 30 y 40 K. El observatorio Spitzer consiste en un telescopio de 0.85 metros con tres instrumentos científicos enfriados criogénicamente, capaces de tomar imágenes y espectros de 3 a 180 micras. Con su gran sensibilidad, su conjunto de detectores de gran formato, su alta efectividad observacional y su larga vida criogénica, Spitzer ofrece una capacidad observacional sin precedentes. El observatorio fué lanzado en Agosto 25, 2003)
Spot The Station (International Space Station (ISS) Sightings. Spot The Station will give you a list of upcoming space station sighting opportunities for your location. Several times a week, Mission Control at NASA's Johnson Space Center in Houston, TX, determines sighting opportunities for over 6,700 locations worldwide. If your specific city or town isn't listed, pick one that is fairly close to you. The space station is visible for a long distance around each of the listed locations)
Suzaku Mission (Formerly Astro-E2. Launched July 10, 2005. Suzaku is Japan's fifth X-ray astronomy mission, and was developed at the Institute of Space and Astronautical Science of Japan Aerospace Exploration Agency (ISAS/JAXA) in collaboration with U.S. (NASA/GSFC, MIT) and Japanese institutions. Suzaku covers the energy range 0.2 - 600 keV with the two instruments, X-ray CCDs (X-ray Imaging Spectrometer; XIS), and the hard X-ray detector (HXD). Suzaku also carries a third instrument, an X-ray micro-calorimeter (X-ray Spectrometer; XRS), but the XRS lost all its cryogen before routine scientific observations could begin)
Terra Satellite (Flagship mission of the Earth Observing System (EOS). Launched in December 1999. Terra carries five instruments that observe Earth's atmosphere, ocean, land, snow and ice, and energy budget. Taken together, these observations provide unique insight into how the Earth system works. Terra observations reveal humanity's impact on the planet and provide crucial data about natural hazards like fire and volcanoes. Terra is an international mission carrying instruments from the United States, Japan, and Canada)
The Exploration of the Earth's Magnetosphere (David P. Stern and Mauricio Peredo. An overview of space research on the Earth's environment in space. The description is non-mathematical but quite detailed)
Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) (Mesosphere and Lower Thermosphere/Ionosphere Mission. Launched in December 7, 2001. By studying portions of Earth's atmosphere, scientists believe global change is occurring, primarily due to variations in the Sun's cycle and from human-induced changes to the atmosphere by the release of gases, such as methane and carbon dioxide. Despite signs of global change, scientists haven't had a benchmark against which future changes in Earth's upper atmosphere can be globally compared, analyzed, or predicted because there are still portions of this Solar-Terrestrial chain, including regions within Earth's atmosphere, that are poorly understood.
The 2-year TIMED mission is studying the influences of the Sun and humans on the least explored and understood region of Earth's atmosphere - the Mesosphere and Lower Thermosphere/Ionosphere (MLTI). The MLTI region is a gateway between Earth's environment and space, where the sun's energy is first deposited into Earth's environment. TIMED is focusing on a portion of this atmospheric region located approximately 40-110 miles (60-180 kilometers) above the surface.
A comprehensive global study of the MLTI region has never before been accomplished. Ground-based instruments can only observe a small portion of the upper atmosphere located over an observation site. This region is too high for balloons to reach. Sounding rockets (rockets that fly into the upper atmosphere for just a few minutes before falling back down) can only provide a brief snapshot of the MLTI region's activity near the rocket)
The Gateway to Astronaut Photography of Earth (NASA Crew Earth Observations. A part of NASA's Space Shuttle Earth Observations Photography database. Our database, the "Gateway to Astronaut Photography of Earth" records the location and a description of over 600,000 astronaut photographs of Earth from the beginning of NASA space flight)
The Great Magnet, the Earth, W. Gilbert (Commemorating the 400th anniversary of "De Magnete" by William Gilbert of Colchester. In 1600, four hundred years ago, William Gilbert, later physician to Queen Elizabeth I of England, published his great study of magnetism, "De Magnete" - "On the Magnet". It gave the first rational explanation to the mysterious ability of the compass needle to point north-south: the Earth itself was magnetic. "De Magnete" opened the era of modern physics and astronomy and started a century marked by the great achievements of Galileo, Kepler, Newton and others. David P. Stern, English, Spanish, French, German, Japanese. Last updated November 20, 2003)
THEMIS Mission (Time History of Events and Macroscale Interactions during Substorms (THEMIS - Understanding Space Weather). NASA's THEMIS aims to resolve one of the oldest mysteries in space physics, namely to determine what physical process in near-Earth space initiates the violent eruptions of the aurora that occur during substorms in the Earth's magnetosphere. THEMIS is a 2-year mission consisting of 5 identical probes that will study the violent colorful eruptions of Auroras. Understanding and predicting space weather is important to describe the environment in which spacecraft and astronauts operate and ensure their safety. Just as hail and tornadoes accompany the most severe thunderstorms, substorms accompany the most intense space storms - those that disrupt communications, cause power line transmission failures, and produce the most penetrating radiation. THEMIS will study substorms to gain insight into the most severe space storms. Launched in February 17, 2007)
The New Mars - Mars 2004 (M2K4) (Multimedia)
The Rossi X-ray Timing Explorer (RXTE) Learning Center (The Rossi X-ray Timing Explorer (RXTE) is a satellite that observes the fast-moving, high-energy worlds of black holes, neutron stars, X-ray pulsars and bursts of X-rays that light up the sky and then disappear forever. Astronomers study changes that happen from microseconds to months in cosmic objects to learn about how gravity works near black holes, how pulsars in binary systems are affected by mass transferring from one star to the other, and how the giant engines in distant galaxies are powered. RXTE was launched into low-Earth orbit on December 30, 1995. It spent over 16 years making unique contributions to our understanding of these extreme objects)
The Swift Gamma-Ray Burst Mission (Gamma-ray bursts (GRBs) are the most powerful explosions the Universe has seen since the Big Bang. They occur approximately once per day and are brief, but intense, flashes of gamma radiation. They come from all different directions of the sky and last from a few milliseconds to a few hundred seconds. So far scientists do not know what causes them. Do they signal the birth of a black hole in a massive stellar explosion? Are they the product of the collision of two neutron stars? Or is it some other exotic phenomenon that causes these bursts? Launched on November 20, 2004)
Tropical Rainfall Measuring Mission (TRMM) (Launched on November 28, 1997, from the Tanegashima Space Center (TNSC) by the H-II F6 launch vehicle. Japan provided the launcher and developed the Precipitation Radar (PR), while NASA developed the spacecraft, four additional observation instruments, and the satellite operation systems.
Assuming a nearly constant propellant usage per maneuver, as has been the case historically, and utilizing the PVT method TRMM is currently expected to run out of usable fuel after maneuver #587 in March 2014.
Utilizing the mass-flow method TRMM is expected to run out of usable fuel after maneuver #617 in January 2016.
Predicted Dates to 13 kg Propellant Remaining:
PVT: Earliest Date: February 2014. Nominal Date: March 2014. Latest Date: August 2014.
Mass Flow: Earliest Date: November 2015. Nominal Date: January 2016. Latest Date: November 2016.
Orbit Decay after Fuel Depletion:
PVT: February 2018
Mass Flow: November 2020
Once the fuel tank has been depleted, the end of mission plan calls for the spacecraft to continue performing science operations until a minimum threshold altitude is reached (335 km), at which point the spacecraft will be passivated.
Since the prime science goal is to keep the 2 prime instruments (TMI and PR) working as long as possible, the key goal seems to be to lessen the load on the battery. So we need to minimize the possibilities of further anomalies, lower the battery charging load, and generally decrease demand on the batteries. As a result, the science team made the decision at this time to keep VIRS turned off)
Van Allen Probes (Observing Earth's Radiation Belt Region. The Van Allen Probes (formerly known as the Radiation Belt Storm Probes (RBSP)) will study two extreme and dynamic regions of space known as the Van Allen Radiation Belts that surround Earth. Named for their discoverer, James Van Allen, these two concentric, donut-shaped rings are filled with high-energy particles that gyrate, bounce, and drift through the region, sometimes shooting down to Earth's atmosphere, sometimes escaping out into space. The radiation belts swell and shrink over time as part of a much larger space weather system driven by energy and material that erupt off the Sun's surface and fill the entire Solar System.
The identical Van Allen Probes will follow similar orbits that will take them through both the inner and outer radiation belts. Space weather is the source of aurora that shimmer in the night sky, but it also can disrupt satellites, cause power grid failures and disrupt GPS communications. The Van Allen Probes will help scientists to understand this region and to better design spacecraft that can survive the rigors of space. While earlier missions have sent back some information about the radiation belts, the Van Allen Probes are the first to use two spacecraft in tandem. As they speed through the belts at some 2000 mph, the spacecraft will naturally pass through changing conditions. But a single moving spacecraft cannot discern whether any changes it observes are due to traveling disturbances, or if the spacecraft simply flew through two static, but differing, regions. Two spacecraft with identical instruments, however, can distinguish between these possibilities. Launched on August 30, 2012, the two Van Allen Probes spacecraft operate in the harsh conditions they are studying. While other satellites have the luxury of turning off or protecting themselves in the middle of intense space weather, the Van Allen Probes must continue to collect data, and therefore, been built to withstand the constant bombardment of particles and radiation they will experience in this intense area of space)
Viking Mission to Mars (NASA's Viking Mission to Mars was composed of two spacecraft, Viking 1 and Viking 2, each consisting of an orbiter and a lander. The primary mission objectives were to obtain high resolution images of the Martian surface, characterize the structure and composition of the atmosphere and surface, and search for evidence of life.
Viking 1 was launched on August 20, 1975 and arrived at Mars on June 19, 1976. The first month of orbit was devoted to imaging the surface to find appropriate landing sites for the Viking Landers. On July 20, 1976 the Viking 1 Lander separated from the Orbiter and touched down at Chryse Planitia (22.48° N, 49.97° W planetographic, 1.5 km below the datum (6.1 mbar) elevation).
Viking 2 was launched September 9, 1975 and entered Mars orbit on August 7, 1976. The Viking 2 Lander touched down at Utopia Planitia (47.97° N, 225.74° W, 3 km below the datum elevation) on September 3, 1976.
The Orbiters imaged the entire surface of Mars at a resolution of 150 to 300 meters, and selected areas at 8 meters. The Viking 2 Orbiter was powered down on July 25, 1978 after 706 orbits, and the Viking 1 Orbiter on August 17, 1980, after over 1,400 orbits.
The Viking Landers transmitted images of the surface, took surface samples and analyzed them for composition and signs of life, studied atmospheric composition and meteorology, and deployed seismometers. The Viking 2 Lander ended communications on April 11, 1980, and the Viking 1 Lander on November 13, 1982, after transmitting over 1400 images of the two sites.
The results from the Viking experiments give our most complete view of Mars to date. Volcanoes, lava plains, immense canyons, cratered areas, wind-formed features, and evidence of surface water are apparent in the Orbiter images. The planet appears to be divisible into two main regions, northern low plains and southern cratered highlands. Superimposed on these regions are the Tharsis and Elysium bulges, which are high-standing volcanic areas, and Valles Marineris, a system of giant canyons near the equator. The surface material at both landing sites can best be characterized as iron-rich clay. Measured temperatures at the landing sites ranged from 150 to 250 K, with a variation over a given day of 35 to 50 K. Seasonal dust storms, pressure changes, and transport of atmospheric gases between the polar caps were observed. The biology experiment produced no evidence of life at either landing site)
Visible Earth (A catalog of NASA images and animations of our home planet)
Wallops Flight Facility (Wallops Flight Facility is located on Virginia's Eastern Shore, it was established in 1945 as a center for aeronautic research. Wallops is now NASA's principal facility for management and implementation of suborbital research programs)
WIND Spacecraft (The Wind spacecraft is the first of two U.S. missions of the Global Geospace Science (GGS) initiative, which is part of a worldwide collaboration called the International Solar-Terrestrial Physics (ISTP) program. The aim of ISTP is to understand the physical behavior of the Solar-Terrestrial system in order to predict how the Earth's magnetosphere and atmosphere will respond to changes in Solar wind. WIND was launched on November 1, 1994, and was positioned in a sunward, multiple double-Lunar swingby orbit with a maximum apogee of 250Re during the first two years of operation. This will be followed by a halo orbit at the Earth-Sun L1 point. WIND plays a crucial role - essentially that of a scout and sentry - in the fleet of ISTP satellites. The task of WIND is to measure crucial properties of the Solar wind before it impacts the Earth's magnetic field and alters the Earth's space environment (which contains charged particles, electric and magnetic fields, electric currents and radiation) and upper atmosphere in a direct manner)
Wide-Field Infrared Survey Explorer (WISE) (Launched in December 2009. The Wide-field Infrared Survey Explorer, or WISE, will scan the entire sky in infrared light, picking up the glow of hundreds of millions of objects and producing millions of images. The mission will uncover objects never seen before, including the coolest stars, the universe's most luminous galaxies and some of the darkest near-Earth asteroids and comets. Its vast catalogs will help answer fundamental questions about the origins of planets, stars and galaxies, and provide a feast of data for astronomers to munch on for decades to come. Thanks to next-generation technology, WISE's sensitivity is hundreds of times greater than its predecessor, the Infrared Astronomical Satellite, which operated in 1983.
WISE will join two other infrared missions in space - NASA's Spitzer Space Telescope and the Herschel Space Observatory, a European Space Agency mission with important NASA participation. WISE is different from these missions in that it will survey the entire sky. It is designed to cast a wide net to catch all sorts of unseen cosmic treasures, including rare oddities.
The closest of WISE's finds will be near-Earth objects, both asteroids and comets, with orbits that come close to crossing Earth's path. The mission is expected to find hundreds of these bodies, and hundreds of thousands of additional asteroids in our Solar System's main asteroid belt. By measuring the objects' infrared light, astronomers will get the first good estimate of the size distribution of the asteroid population. This information will tell us approximately how often Earth can expect an encounter with a potentially hazardous asteroid. WISE data will also reveal new information about the composition of near-Earth objects and asteroids - are they fluffy like snow or hard like rocks, or both?
The next closest targets for WISE are dim stars called brown dwarfs. These Jupiter-like balls of gas form like stars but fail to gather up enough mass to ignite like stars. The objects are cool and faint, and nearly impossible to see in visible light. WISE should uncover about 1,000 in total, and will double or triple the number of star-like objects known within 25 light-years of Earth. What's more, if a brown dwarf is lurking closer to us than the closest known star, Proxima Centauri, WISE will find it and the little orb will become famous for being the "closest known star".
The most distant objects that will stand out like ripe cherries in WISE's view are tremendously energetic galaxies. Called ultraluminous infrared galaxies, or ULIRGs, these objects shine with the light of up to a trillion suns. They crowd the distant universe, but appear virtually absent in visible-light surveys. WISE should find millions of ultra-luminous infrared galaxies, and the most luminous of these could be the most luminous galaxy in the universe.
Other nuggets to come out of the WISE survey will be newborn stars; disks of planetary debris around young stars; a detailed look at the structure of our Milky Way galaxy; clusters of galaxies in the far universe and more. The most interesting finds will lay the groundwork for follow-up studies with other missions, such as NASA's Spitzer Space Telescope, the Herschel Space Observatory, NASA's Hubble Space Telescope, NASA's upcoming SOFIA airborne telescope and NASA's upcoming James Webb Space Telescope. Powerful ground-based telescopes will also follow up on WISE discoveries)
Wilkinson Microwave Anisotropy Probe (WMAP) - Cosmology (Temperature differences in the cosmic microwave background radiation. Launched on June 30, 2001, maneuvered to its observing station near the "second Lagrange point" of the Earth-Sun system, a million miles from Earth in the direction opposite the Sun. The WMAP science team has determined, to a high degree of accuracy and precision, not only the 13.7 billion years age of the universe, but also the density of atoms: 4.6% of the universe, the density of all other non-atomic matter: some kind of an anti-gravity energy makes up 73% of the universe; the epoch when the first stars started to shine: about 400 million years after the Big Bang; the "lumpiness" of the universe, and how that "lumpiness" depends on scale size. WMAP has been stunningly successful, producing our new Standard Model of Cosmology. The (mis-named) "Big Bang" framework of cosmology, which posits that the young universe was hot and dense, and has been expanding and cooling ever since, is now solidly supported, according to WMAP. WMAP observations also support an add-on to the big bang framework to account for the earliest moments of the universe. Called "inflation", the theory says that the universe underwent a dramatic early period of expansion, growing by more than a trillion trillion-fold in less than a trillionth of a trillionth of a second. Tiny fluctuations were generated during this expansion that eventually grew to form galaxies. WMAP completed its prime 2 years of mission operations in its L2 orbit by September 2003. The first WMAP results were issued in February 2003, with major updates in 2005, 2007, 2009, 2011, and the final release in 2011)
 - WMAP's Introduction to Cosmology (Universe 101 - Big Bang Theory - Cosmology: The Study of the Universe. Cosmology is the scientific study of the large scale properties of the universe as a whole. It endeavors to use the scientific method to understand the origin, evolution and ultimate fate of the entire Universe)

NASA - Jet Propulsion Laboratory (JPL):
Jet Propulsion Laboratory Home Page (Space, Stars, Mars, Earth, Planets and More. Officially named in 1944)
Active Cavity Radiometer Irradiance Monitor (ACRIM) (Total Solar Irradiance measuring mission. The Active Cavity Radiometer Irradiance Monitor (ACRIM I) instrument was the first to clearly demonstrate that the total radiant energy from the Sun was not a constant. However, the Solar variability was so slight (0.1% of full scale) that continuous monitoring by state-of-the-art instrumentation was necessary. It is theorized that as much as 25% of the anticipated global warming of the Earth may be Solar in origin. In addition, seemingly small (0.5%) changes in the TSI output of the Sun over a century or more may cause significant climatological changes on Earth. ACRIMSAT was launched in December 1999, carries the Acrim III instrument. ACRIMSAT completed its five-year primary mission in May 20, 2005)
Airborne Synthetic Aperture Radar (AirSAR) (The Airborne Synthetic Aperture Radar (AIRSAR) was an all-weather imaging tool able to penetrate through clouds and collect data at night. The longer wavelengths could also penetrate into the forest canopy and in extremely dry areas, through thin sand cover and dry snow pack. AIRSAR first flew in 1988, and flew its last mission in 2004)
Asteroid Radar Research (Radar is a uniquely powerful source of information about asteroid physical properties and orbits. Measurements of the distribution of echo power in time delay (range) and Doppler frequency (radial velocity) constitute two-dimensional images that can provide spatial resolution finer than 10 meters if the echoes are strong enough. With adequate orientational coverage, such images can be used to construct geologically detailed three-dimensional models, to define the rotation state precisely, and to constrain the object's internal density distribution. Moreover, radar wavelengths are sensitive to near-surface bulk density and structural scales larger than a few centimeters.
The world's two primary facilities used for planetary radar astronomy are the National Astronomy and Ionosphere Center's Arecibo Observatory in Puerto Rico and NASA's Goldstone Solar System Radar (part of the Deep Space Network) in California. Arecibo has twice the range and can see three times the volume of Goldstone, while Goldstone, whose greater steerability provides twice the sky coverage and much longer tracking times, serves a complementary role)
Atmospheric Infrared Sounder (AIRS) (The Atmospheric Infrared Sounder, AIRS, is a facility instrument whose goal is to support climate research and improve weather forecasting. Launched into Earth orbit on May 4, 2002, aboard NASA's Aqua satellite, AIRS moves climate research and weather prediction into the 21st century. AIRS is one of six instruments onboard Aqua, which is part of NASA's Earth Observing System of satellites)
Cassini Solstice Mission (Saturn system. Cassini completed its initial four-year mission to explore the Saturn System in June 2008 and the first extended mission, called the Cassini Equinox Mission, in September 2010. Now, the healthy spacecraft is seeking to make exciting new discoveries in a second extended mission called the Cassini Solstice Mission. The mission's extension, which goes through September 2017, is named for the Saturnian summer solstice occurring in May 2017. The northern summer solstice marks the beginning of summer in the northern hemisphere and winter in the southern hemisphere. Since Cassini arrived at Saturn just after the planet's northern winter solstice, the extension will allow for the first study of a complete seasonal period. Cassini launched in October 1997 with the European Space Agency's Huygens probe. The probe was equipped with six instruments to study Titan, Saturn's largest moon. It landed on Titan's surface on January 14, 2005, and returned spectacular results. Meanwhile, Cassini's 12 instruments have returned a daily stream of data from Saturn's system since arriving at Saturn in 2004. Among the most important targets of the mission are the moons Titan and Enceladus, as well as some of Saturn' other icy moons. Towards the end of the mission, Cassini will make closer studies of the planet and its rings)
Comet Shoemaker-Levy 9 Collision with Jupiter (From July 16 through July 22, 1994, pieces of an object designated as Comet P/Shoemaker-Levy 9 collided with Jupiter. This is the first collision of two solar system bodies ever to be observed, and the effects of the comet impacts on Jupiter's atmosphere have been simply spectacular and beyond expectations. Comet Shoemaker-Levy 9 consisted of at least 21 discernable fragments with diameters estimated at up to 2 kilometers.
July 16, 2014 Update: 20 years later: Twenty years ago, Comet Shoemaker-Levy 9 (SL9) impacted Jupiter. Ron Baalke created this website in June 1994 on a voluntary basis, and it was his first public website. He was immensely interested in this unique comet since its discovery in 1993 - a comet that was not only captured into Jupiter orbit, but had broken up into several pieces which were about to hit Jupiter in July 1994. There were a lot of speculation about how the impacts would appear on Jupiter, and this website documents each impact as they occurred. Also note: back in 1994, websites were relatively unknown and somewhat of a novelty. This website became the first big Web event, and was key in raising the awareness of websites to the mainstream public, which we now take for granted today)
Dawn Mission (Dawn's goal is to characterize the conditions and processes of its earliest history by investigating in detail two of the largest protoplanets remaining intact since their formation. Ceres and Vesta reside in the main asteroid belt, the extensive region between Mars and Jupiter, along with many other smaller bodies. Each followed a very different evolutionary path, constrained by the diversity of processes that operated during the first few million years of Solar System evolution. When Dawn visits Ceres and Vesta, the spacecraft steps us back in Solar System time. Ion Propulsion. Asteroids Vesta (July 2011 to September 2012) and Ceres (Spring 2015). Launched in September 27, 2007)
Deep Space Network (DSN) (Spacecraft Communications, Radio & Radar Astronomy. The largest and most sensitive scientific telecommunications system in the world. The Deep Space Network - or DSN - is NASA's international array of giant radio antennas that supports interplanetary spacecraft missions, plus a few that orbit Earth. The DSN also provides radar and radio astronomy observations that improve our understanding of the solar system and the larger universe.
The DSN consists of three facilities spaced equidistant from each other - approximately 120 degrees apart in longitude - around the world. These sites are at Goldstone, near Barstow, California; near Madrid, Spain; and near Canberra, Australia. The strategic placement of these sites permits constant communication with spacecraft as our planet rotates - before a distant spacecraft sinks below the horizon at one DSN site, another site can pick up the signal and carry on communicating)
Fundamental Physics in Space (Why Things Are The Way They Are. NASA's Fundamental Physics in Space Program seeks to understand how simple laws and organizing principles of nature affect matter, space, and time. Our quest is to understand why the Universe developed into what we observe today - in short, why things are the way they are. In that pursuit, we'll be looking for connections at all levels - from subatomic particles all the way up to great galaxies - hoping to build a comprehensive picture of our world)
Genesis Mission (Solar Wind Sample Return. About 4.6 billion years ago, the Solar nebula transformed into the present Solar System. In order to chemically model the processes which drove that transformation, we would, ideally, like to have a sample of that original nebula to use as a baseline from which we can track changes. NASA's Genesis sample-return mission is designed to give us just such a baseline composition. It has collected Solar wind, material which is ejected from the outer portion of the Sun, and returned it to Earth. Genesis was launched in August 2001. It traveled to L1 Lagrange Point, where it stayed in a halo orbit for 886 days passively collected Solar-wind samples; i.e., ions from the Solar-wind impacted collectors at speeds over 200 km/sec and buried themselves in specially-selected materials.
After the collection period, the spacecraft closed-up and returned the samples to Earth in a Stardust-like sample-return capsule (SRC). On 8 September 2004 the SRC entered Earth's atmosphere as planned, but its gravity switches were oriented incorrectly as the result of a design error and the parachute system failed to deploy. The high-speed wreck compromised the SRC and shattered many of the Genesis collectors. However, the Genesis Preliminary Examination Team was able to show that, because the Solar-wind ions were buried beneath the surface of the collectors, it is possible to detect and quantify elements in the Solar-wind. Accordingly, in March 2005, Johnson Space Center curatorial staff started allocating Solar-wind collectors to the international scientific community. Each allocation will allow scientists to glean information on the composition of the Solar wind, thereby completing the circle and allowing us to piece together the chemical and isotopic composition of the Solar nebula which formed our Solar System. The cosmochemical and Solar research on Genesis samples will continue for decades)
Keck Interferometer (The Keck Interferometer combines the light from the twin Keck Telescopes (10-meter (33 feet)) atop Mauna Kea, Hawaii, to create an instrument equal in power to an 85-meter telescope. Astronomers use the interferometer, which provides vital information about exoplanets and planetary formation, to measure the diameters of stars, disks orbiting nearby stars and the orbital characteristics of binary systems)
Mars Climate Orbiter / Mars Polar Lander Mission (NASA has initiated a long-term systematic program of Mars exploration, the Mars Surveyor Program (MSP). The highest priority scientific objectives of this program are to: Search for evidence of past or present life, Understand the climate and volatile history of Mars, Assess the nature and inventory of resources on Mars. The Mars Climate Orbiter was launched in December 1998, and arrived at Mars in September 1999. The Mars Polar Lander was launched in January 1999, and arrived at Mars in December 3, 1999. By February 1, 2000 there was no response from the Mars Polar Lander. All communication attempts ended on January 17, 2000)
Mars Exploration Program (Since our first close-up picture of Mars in 1965, spacecraft voyages to the Red Planet have revealed a world strangely familiar, yet different enough to challenge our perceptions of what makes a planet work. Over the past three decades, spacecraft have shown us that Mars is rocky, cold, and dry beneath its hazy, pink sky. We've discovered that today's Martian wasteland hints at a formerly volatile world where volcanoes once raged, meteors plowed deep craters, and flash floods rushed over the land. Among our discoveries about Mars, one stands out above all others: the possible presence of liquid water on Mars, either in its ancient past or preserved in the subsurface today)
 - Mars Exploration Program: Technology (Technology development makes missions possible)
 - 2001 Mars Odyssey (A long-term effort of robotic exploration of Mars. Launched on April 7, 2001. Arrived on October 24, 2001. Odyssey's primary science mission took place from February 2002 through August 2004. For the first time, the mission globally mapped the amount and distribution of many chemical elements and minerals that make up the Martian surface. Maps of hydrogen distribution led scientists to discover vast amounts of water ice in the polar regions burried just beneath the surface. Odyssey also recorded the radiation environment in low Mars orbit to determine the radiation-related risk to any future human explorers who may one day go to Mars. The orbiter began its extended missions on August 24, 2004)
 - Mars Exploration Rover Mission (The twin robot geologists in search of answers about the history of water on Mars. Targeted to sites on opposite sides of Mars that appear to have been affected by liquid water in the past. To search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. Spirit launched on June 10 and Opportunity on July 7, 2003. Spirit landed on January 3 and Opportunity on January 24, 2004)
Mars Global Surveyor (MGS) (Launched on November 7, 1996. Reached Mars on September 11, 1997. The mapping phase of the mission began in mid-March 1999. After mapping finished in late January 2000, the spacecraft will function as a communications satellite to relay data back to Earth from surface landers launched as part of future Mars missions)
 - The Mars Orbiter Laser Altimeter (MOLA) (The Mars Orbiter Laser Altimeter, or MOLA, is an instrument on the Mars Global Surveyor (MGS). The Mars Global Surveyor launched on November 7, 1996. It traveled towards Mars for 309 days, entering orbit on September 12, 1997. The mission of MGS was to orbit Mars, and map it over the course of approximately 3 years, which it did sucessfully, completing 4 1/2 years of mapping)
 - Mars Science Laboratory (To study Mars' habitability. With Curiosity, the Mars rover, designed to assess whether Mars ever had an environment able to support small life forms called microbes. Launched November 26, 2011. Arrived on August 6, 2012)
Mars Meteorites Home Page (Of the 60,000 or so meteorites that have been discovered on Earth, only 124 have been identified as originating from the planet Mars. By Ron Baalke)
Mars Pathfinder Mission (Before and after the July 4, 1997 landing. Rover Sojourner. Launched in December 1996. Completed Surface Mission in August 1997. End Of Project in September 1998)
Near-Earth Asteroid Tracking (NEAT) (NEAT is comprised of two autonomous observing systems at Maui Space Surveillance Site, NEAT/MSSS, and at Palomar Observatory, NEAT/Palomar. At both sites the NEAT cameras use 1.2-m (48") telescopes to find Near-Earth objects (NEOs), both Near-Earth asteroids (NEAs) and comets)
Near-Earth Object Program (NEO) (Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighborhood. Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter. The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged remnant debris from the Solar System formation process some 4.6 billion years ago. The giant outer planets (Jupiter, Saturn, Uranus, and Neptune) formed from an agglomeration of billions of comets and the left over bits and pieces from this formation process are the comets we see today. Likewise, today's asteroids are the bits and pieces left over from the initial agglomeration of the inner planets that include Mercury, Venus, Earth, and Mars. By Don Yeomans, Ron Baalke)
 - NEO Earth Close Approaches (Custom tables (updated daily) showing future and past NEO close-approach data)
New Millennium Program (NMP) (Advanced Technology in Space Flight. Before new, untried technologies are used for the first time on complex exploration missions, engineers and scientists want to make sure they will operate well, and safely, in the hazardous environment of space. To accomplish this, NASA's Office of Space Science (OSS) and Office of Earth Science jointly established the New Millennium Program (NMP) in 1995 - an ambitious, exciting vision to speed up space exploration through the development and testing of leading-edge technologies)
Ocean Surface Topography from Space (TOPEX/Poseidon and Jason satellites. Earth's oceans are the greatest influence on global climate. Only from space can we observe our vast oceans on a global scale and monitor critical changes in ocean currents and heat storage. Continuous data from satellites like TOPEX/Poseidon and Jason help us understand and foresee the effects of the changing oceans on our climate.
Since 1992 NASA, NOAA and our European partners have been tracking global ocean surface topography with joint ocean altimeter satellite missions from an orbit 1,336 km above the ocean surface, The spacecrafts' radar altimeters measure the precise distance between the satellite and sea surface. The details of the shape of the returned radar pulses also give information on wind speed and the wave height. Ocean altimeter missions monitor large-scale features like Rossby and Kelvin waves, track El Niño's like the large event of 1997-1998 and the subsequent La Niña events, and explores long-term changes such as the Pacific Decadal Oscillation. The high accuracy of these measurements has made satellite altimetry an efficient method for monitoring the variation of global mean sea level in relation to global climate change. TOPEX/Poseidon was joined in 2001, and later replaced after the conclusion of a Tandem Mission, by Jason-1, which continues to build the database. The two GRACE (the Gravity Recovery and Climate Experiment) spacecrafts, which launched March 2002, are refining global measurements, increasing the utility of all previous altimetry data. The Ocean Surface Topography Mission or Jason-2 (OSTM/Jason-2), launched in June 2008, is taking ocean surface topography measurements into an operational mode for continued climate forecasting research as well as scientific and industrial applications)
Photojournal (Your interface to the Planetary Image Archive (PIA) contained within the Planetary Data System Imaging Node. The home page graphic serves as a high-level entry point to the thousands of high-resolution images and their accompanying products which have been made available to the public from data returned by various JPL missions over the course of many years. We also provide a number of search mechanisms to aid you with in-depth searches from the database for images from specific missions, spacecraft, and/or instruments aboard the spacecraft)
Physical Oceanography Distributed Active Archive Center (PO.DAAC) (Ocean Surface Topography, Ocean Vector Winds, Sea Surface Temperature) (An element of the Earth Observing System Data and Information System (EOSDIS). The mission of the PO.DAAC is to preserve NASA's ocean and climate data and make these universally accessible and meaningful. Since the launch of NASA's first ocean-observing satellite, Seasat, in 1978, PO.DAAC has become the premier data center for measurements focused on ocean surface topography (OST), sea surface temperature (SST), ocean winds, sea surface salinity (SSS), gravity, ocean circulation and sea ice)
PlanetQuest: Exoplanet Exploration (Are we alone? Are their other planets like ours? Does life exist elsewhere in the universe? These are questions mankind has been asking for years - since the time of Greek philosophers. But for years, those answers have been elusive, if not impossible to find. Even more exciting is the fact that astronomers are in hot pursuit of the first discovery of an Earthlike exoplanet orbiting a star other than the Sun)
Planck Space Telescope (ESA & NASA. The Planck mission, launched on May 14, 2009, is measuring the Cosmic Microwave Background (CMB) over a broad range of far-infrared wavelengths, and to an unprecedented accuracy. The measurements will enable the extraction of essentially all of the information that can be obtained from CMB temperature anisotropies. Planck is expected to provide answers to many fundamental questions about the early history and evolution of our universe)
Shuttle Radar Topography Mission (SRTM) (The Shuttle Radar Topography Mission (SRTM) obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth. SRTM consisted of a specially modified radar system that flew onboard the Space Shuttle Endeavour during an 11-day mission in February of 2000)
Solar System Dynamics (This site provides information related to the orbits, physical characteristics, and discovery circumstances for most known natural bodies in orbit around our Sun. Ephemerides, Orbits, Physical Characteristics, Discovery Circumstances, On-Line Tools)
 - JPL HORIZONS On-Line Solar System Data and Ephemeris Computation Service (The JPL HORIZONS on-line Solar System data and ephemeris computation service provides access to key Solar System data and flexible production of highly accurate ephemerides for Solar System objects (645,157 asteroids, 3,279 comets, 178 planetary satellites, 8 planets, the Sun, L1, L2, select spacecraft, and system barycenters)
 - Small-Body Database Browser (With Orbit Diagrams. The JPL Small-Body Database Browser provides data for all known asteroids and many comets. Enter the IAU number, name, or designation for the object of interest in the Search form)
Solar System Simulator (Initially developed in the late 1970's and 80's by highly acclaimed computer graphics expert Jim Blinn, SPACE continued to serve as an outstanding mission design tool for many years. In April through June of 1997, David Seal rebuilt the SPACE software set in ANSI C, standardized its interface, input and output file formats, added some new features, and installed it on the World Wide Web. The new software now drives the web-based Solar System Simulator, which can create a color image of any planet or satellite as seen from any point in the Solar System)
Space Calendar (The Space Calendar covers space-related activities and anniversaries for the coming year. Included are over 4,100 links to related home pages. This Calendar is compiled and maintained by Ron Baalke)
Stardust Mission (Interstellar and Comet Wild 2 Dust Sample Return Mission. February 7, 1999 - January 15, 2006. Stardust was the first U.S. space mission dedicated solely to the exploration of a comet, and the first robotic mission designed to return extraterrestrial material from outside the orbit of the Moon. The primary goal of Stardust was to collect dust and carbon-based samples during its closest encounter with Comet Wild 2 - pronounced "Vilt 2" after the name of its Swiss discoverer - is a rendezvous scheduled to take place in January 2004, after nearly four years of space travel
Additionally, the Stardust spacecraft would bring back samples of interstellar dust, including recently discovered dust streaming into our Solar System from the direction of Sagittarius. These materials are believed to consist of ancient pre-Solar interstellar grains and nebular that include remnants from the formation of the Solar System. Analysis of such fascinating celestial specks is expected to yield important insights into the evolution of the Sun its planets and possibly even the origin of life itself.
In order to meet up with comet Wild 2, the spacecraft made three loops around the Sun. On the second loop, its trajectory intersected the comet. During the meeting, Stardust performed a variety of tasks including reporting counts of comet particles encountered by the spacecraft with the Dust Flux Monitor, and real-time analyses of the compositions of these particles and volatiles taken by the Comet and Interstellar Dust Analyzer (CIDA). Using a substance called aerogel, Stardust captured these samples and stored them for safe keep on its long journey back to Earth. This silica-based, material has been inserted within the Aerogel Collector Grid, which is similar to a large tennis racket. Not until January 2006, would Stardust and its precise cargo return by parachuting a reentry capsule weighing approximately 125 pounds to the Earth's surface) [Stardust failed to deploy its parachute after re-entry and crashed in the desert. The Genesis Mission sample return capsule shattered but was recovered and is now being analyzed to salvage some of the collections]
Ulysses Mission (Sun Orbiter. The Shuttle Discovery launched the Ulysses spacecraft on October 6, 1990. To reach high Solar latitudes, the spacecraft was aimed close to Jupiter so that Jupiter's large gravitational field would accelerate Ulysses out of the ecliptic plane to high latitudes.
The encounter with Jupiter occurred on February 8, 1992, and since then Ulysses traveled to higher latitudes with maximum Southern latitude of 80.2 degrees being achieved on September 13, 1994. Ulysses traveled through high Northern latitudes during June through September 1995. These high latitude observations were obtained during the quiet (minimum) portion of the 11-year solar cycle.
In order to fully understand our amazing star, it was necessary to study the Sun at near maximum conditions. During the Solar Maximum mission, Ulysses reached maximum Southern latitude on November 27, 2000, and traveled through High Northern latitude September through December 2001.
After more than 12 years in flight, Ulysses has returned a wealth of data that has led to a much broader understanding of the Global Structure of the Sun's environment - the heliosphere.
June 30, 2009: On June 10, 2009, Ulysses became the longest-running ESA-operated spacecraft. The Ulysses orbital path was carrying the spacecraft away from Earth. The ever-widening gap has progressively limited the amount of data transmitted. Ulysses project managers, with the concurrence of ESA and NASA, decided it was an appropriate time to end this epic scientific adventure)
Voyager Mission (Voyager 1 & 2: 1977-2020? The twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing on their more-than-35-year journey since their 1977 launches, they each are much farther away from Earth and the Sun than Pluto. In August 2012, Voyager 1 made the historic entry into interstellar space, the region between stars, filled with material ejected by the death of nearby stars millions of years ago. Scientists hope to learn more about this region when Voyager 2, in the "heliosheath" - the outermost layer of the heliosphere where the Solar wind is slowed by the pressure of interstellar medium - also reaches interstellar space. Both spacecraft are still sending scientific information about their surroundings through the Deep Space Network, or DSN.
The primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there - such as active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings - the mission was extended. Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets. The adventurers' current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun's domain. And beyond)
Welcome to the Planets (PDS) (This is a collection of many of the best images from NASA's planetary exploration program. The collection has been extracted from the interactive program "Welcome to the Planets" which was distributed on the Planetary Data System Educational CD-ROM Version 1.5 in December 1995. It has also been updated with the addition of more recent images)
Winds Mission (Measuring Ocean Winds from Space. One of the fundamental problems faced by oceanographers is the sheer size of the oceans. Oceans cover 70 per cent of the Earth's surface. Remote sensing allows measurements to be made of vast areas of ocean repeated at intervals in time.
As the largest source of momentum for the ocean surface, winds affect the full range of ocean movement - from individual surface waves to complete current systems. Winds over the ocean modulate air-sea exchanges of heat, moisture, gases, and particulates. This modulation regulates the interaction between the atmosphere and the ocean, which establishes and maintains both global and regional climates.
The tropical Pacific Ocean and overlying atmosphere react to, and influence each other. Easterly surface winds along the equator control the amount and temperature of the water that upwells (moves or flows upward) to the surface. This upwelling of cold water determines sea-surface temperature distribution, which affects rainfall distribution. This in turn determines the strength of the easterly winds - a continuous cycle)

National Oceanic and Atmospheric Administration (NOAA):
National Oceanic and Atmospheric Administration Home Page
Atlantic Oceanographic and Meteorological Laboratory (AOML)
 - Hurricane FAQ (con versión en Español)
Climate Prediction Center (CPC)
Coastal Services Center
Deep Space Climate Observatory (DSCOVR) (Earth & Solar observatory at Lagrange Point L1. Launched Feb. 11, 2015)
 - EPIC Earth Polychromatic Camera (Full, sunlit side of the Earth)
Earth System Research Laboratory (ESRL)
 - Chemical Sciences Division (CSD)
 - Global Monitoring Division (GMD)
    - Solar Calculator (Sunrise, Sunset, Solar Noon and Solar Position for Any Place on Earth. Google Earth interface)
     - Solar Position Calculator (Old version)
     - Improved Sunrise/Sunset Calculator (Old version)
 - Physical Sciences Division (PSD) (Climate Variability)
El Niño Theme Page (Distributed information on El Niño)
Geophysical Fluid Dynamics Laboratory (GFDL)
National Climatic Data Center (NCDC)
National Data Buoy Center
National Environmental Satellite, Data, and Information Service (NESDIS)
 - Office of Satellite Data Processing and Distribution (OSDPD)
National Geophysical Data Center (NGDC)
 - ETOPO1 Global Relief (1 arc-minute model of Earth's surface that integrates land topography and ocean bathymetry)
National Hurricane Center - Tropical Prediction Center
National Oceanographic Data Center (Marine data and information)
National Operational Hydrologic Remote Sensing Center (Snow information)
National Severe Storms Laboratory
National Weather Service (NWS) Home Page
 - Internet Weather Source
 - Ocean Prediction Center - Unified Surface Analysis
 - National Doppler Radar Sites
 - NOAA/NWS Storm Prediction Center
 - NOAA - Tsunami Warning Center
 - Space Weather Prediction Center
NOAA Tides and Currents (Center for Operational Oceanographic Products and Services (CO-OPS))

European Space Agency (ESA):
European Space Agency Home Page (The European Space Agency (ESA) is Europe's gateway to space. Its mission is to shape the development of Europe's space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
ESA started with the creation of two entities, entering into force in 1964, the European Launcher Development Organisation (ELDO) and the European Space Research Organisation (ESRO). In 1973 the European Space Agency (ESA) was established, replacing these two organisations.
ESA - Space Science:
Giotto - Mission to Comet Halley (Launched on July 2, 1985, ESA's first deep space mission, Giotto was designed to help solve the mysteries surrounding Comet Halley by passing as close as possible to the comet's nucleus, which it achieved on March 13, 1986. No-one expected the spacecraft to survive its battering from comet dust during this encounter, but although Giotto was damaged during the flyby, most of its instruments remained operational. The mission was extended to allow an unprecedented encounter with a second comet, Grigg-Skjellerup.
11 March 2011: Twenty-five years ago, on the night of March 13-14 1986, ESA made its mark in deep space. A small spacecraft swept to within 600 km of Halley's comet. The Giotto probe was nearly destroyed by the encounter but what it saw changed our picture of comets forever. By measuring its composition, Giotto confirmed Halley as a primitive remnant of the Solar System, billions of years old. It detected complex molecules locked in Halley's ices that could have provided the chemical building blocks of life on Earth. Just 10x15 km, it surprised everyone by being darker than coal, reflecting just 4% of the light falling on its surface. Instead of the whole surface boiling away, jets were localised in specific areas. Giotto nearly did not survive. As expected, the probe was pummelled. Ripping into it at speeds of 68 km/s, dust from the comet eroded away the shielding and the sensors, destroying the camera. But Giotto itself lived on and was sent to meet a second comet, Grigg-Skjellerup, in 1992.
On July 2, 1990, Giotto's orbit was altered as it zipped past the Earth, just 22,730 km above the cloud tops. This was the first time a spacecraft coming from deep space had used the Earth for a gravity assist. During the flyby, observations were made of the Earth's magnetic field and energetic particle environment. After another prolonged hibernation, Giotto's payload was switched on in the evening of July 9, 1992. The Grigg-Skjellerup flyby took place the following day, about 215 million km from Earth. Giotto crossed the bow shock and entered the dust coma about 17,000 km from the comet. Aimed directly at the nucleus, Giotto missed by a mere 100 to 200 km, eventually passing by on the night side at 15:30 GMT. It was the closest ever cometary flyby. The science experiments were switched off for the last time on July 11, 1992. After some minor orbit manoeuvres, the spacecraft was once more shut down on July 23, 1992. There were no plans to revive it)
Hipparcos Space Astrometry Mission - Tycho Catalogues (ESA's Hipparcos space astrometry mission was a pioneering European project which pinpointed the positions of more than one hundred thousand stars with high precision, and more than one million stars with lesser precision. Launched in August 8, 1989 Hipparcos successfully observed the celestial sphere for 3.5 years before operations ceased in March 1993.
Calculations from observations by the main instrument generated the Hipparcos Catalogue of 118,218 stars charted with the highest precision. An auxiliary star mapper pinpointed many more stars with lesser but still unprecedented accuracy, in the Tycho Catalogue of 1,058,332 stars. The Tycho 2 Catalogue, completed in 2000, brings the total to 2,539,913 stars, and includes 99% of all stars down to magnitude 11, almost 100 000 times fainter than the brightest star, Sirius. This web site presents background information describing the mission, the satellite and payload, operations and data reduction procedures. The Hipparcos and Tycho catalogues are described, and details on how to access the catalogues are provided. Some scientific highlights from the mission are noted. A number of resources are provided indicating how the Hipparcos and Tycho data can be used as educational tools. Visual material, in the form of photographs, images and animations are available for use)
Infrared Space Observatory (ISO) (The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths. The two spectrometers (SWS and LWS), a camera (ISOCAM) and an imaging photo-polarimeter (ISOPHOT) jointly covered wavelengths from 2.5 to around 240 microns with spatial resolutions ranging from 1.5 arcseconds (at the shortest wavelengths) to 90 arcseconds (at the longer wavelengths). Its 60 cm diameter telescope was cooled by superfluid liquid helium to temperatures of 2-4 K.
The mission was a great technical, operational and scientific success with most satellite sub-systems operating far better than specifications and with its scientific results impacting practically all fields of astronomy. During its routine operational phase, which lasted until April 1998 - almost a year longer than specified, ISO successfully made some 30,000 individual imaging, photometric, spectroscopic and polarimetric observations ranging from objects in our own solar system right out to the most distant extragalactic sources. In the ensuing Post Operational Phases, which ended in 2006, the ISO archive has been improved and enhanced both in functionality and in contents, in order to maximise its long-term value and usability, as a legacy to future generations of astronomers)
Solar and Heliographic Observatory (SOHO) (SOHO, the Solar & Heliospheric Observatory, is a project of international collaboration between ESA and NASA to study the Sun from its deep core to the outer corona and the solar wind.
SOHO was launched on December 2, 1995. The SOHO spacecraft was built in Europe by an industry team led by prime contractor Matra Marconi Space (now EADS Astrium) under overall management by ESA. The twelve instruments on board SOHO were provided by European and American scientists. SOHO moves around the Sun in step with the Earth, by slowly orbiting around the First Lagrangian Point (L1), where the combined gravity of the Earth and Sun keep SOHO in an orbit locked to the Earth-Sun line. The L1 point is approximately 1.5 million kilometers away from Earth (about four times the distance of the Moon), in the direction of the Sun. There, SOHO enjoys an uninterrupted view of our daylight star. All previous solar observatories have orbited the Earth, from where their observations were periodically interrupted as our planet 'eclipsed' the Sun.
An unexpected loss of contact with SOHO occurred on June 25, 1998. Fortunately, the mission was completely recovered in one of the most dramatic rescue efforts in space, and normal operations could be resumed in mid-November 1998 after the successful recommissioning of the spacecraft and all 12 instruments. Despite the subsequent failures of all three gyroscopes (the last in December 1998), new gyroless control software installed by February 1999 allowed SOHO to return to normal scientific operations, making SOHO the first 3-axis-stabilised spacecraft to operate without a gyroscope)
Cassini/Huygens mission (A joint NASA/ESA/ASI mission to Saturn, Titan, Enceladus and Dione.
Christiaan Huygens (1629-1695) was a Dutch scientist who discovered Saturn's rings and, in 1655, its largest moon, Titan. Italian Jean-Dominique Cassini (1625-1712) discovered the Saturnian satellites Iapetus, Rhea, Tethys and Dione. In 1675 he discovered what is known today as the 'Cassini Division', the narrow gap separating Saturn's rings.
Launched October 15, 1997, the Cassini/Huygens spacecraft arrived at Saturn in July 2004. In December 2004, towards the end of Cassini's third orbit around Saturn, the Huygens probe was ejected on a 22-day cruise to Titan. Huygens reached Titan on January 14, 2005. Cassini is in operation, orbiting around Saturn)
XMM-Newton (Launched from Kourou, French Guiana on December 10, 1999, the European Space Agency's X-ray Multi-Mirror satellite XMM-Newton is the most powerful X-ray telescope ever placed in orbit. The mission is helping to solve many cosmic mysteries, ranging from enigmatic black holes to the formation of galaxies.
ESA's X-ray space observatory XMM-Newton is unique. It is the biggest scientific satellite ever built in Europe, its telescope mirrors are amongst the most powerful ever developed in the world, and with its sensitive cameras it can see much more than any previous X-ray satellite.
Many celestial objects generate X-rays in extremely violent processes. But Earth's atmosphere blocks out these X-rays, messengers of what occurred in the distant past when stars were born or died, and clues to our future. Only by placing X-ray detectors in space can such sources be detected, pinpointed and studied in detail. XMM-Newton, the largest science satellite ever built in Europe, has an unprecedented sensitivity.
XMM-Newton carries three very advanced X-ray telescopes. They each contain a mirror module with 58 high-precision concentric mirrors, delicately nested to offer the largest collecting area possible to catch the elusive X-rays. These mirror modules allow XMM-Newton to detect millions of sources, far more than any previous X-ray mission.
The satellite follows a highly eccentric orbit, travelling out to nearly one third of the distance to the Moon; this enables astronomers to make very long and uninterrupted observations. Peering into deep space, XMM-Newton's science payload is considerably increasing our knowledge of very hot objects created when the Universe was very young.
XMM-Newton is the second of ESA's four 'Cornerstone' missions defined in the Horizon 2000 Programme. Development and construction of the spacecraft overcame major technological hurdles. Its wafer-thin X-ray mirrors are an extraordinary feat of engineering and the smoothest ever built. With its five X-ray imaging cameras and spectrographs, and its optical monitoring telescope, the space observatory is at the cutting edge of astronomy)
Gravity field and steady-state Ocean Circulation Explorer (GOCE) (Launched in March 2009, GOCE has mapped variations in Earth's gravity with unrivalled precision. The result is the most accurate shape of the 'geoid' - a hypothetical global ocean at rest - ever produced, which is being used to understand ocean circulation, sea level, ice dynamics and Earth's interior.
Close to 01:00 CET on Monday November 11, 2013, ESA's GOCE satellite reentered Earth's atmosphere on a descending orbit pass that extended across Siberia, the western Pacific Ocean, the eastern Indian Ocean and Antarctica. As expected, the satellite disintegrated in the high atmosphere and no damage to property has been reported.
GOCE's innovative ion engine, responsible for keeping the satellite at an incredibly low orbit of under 260 km, together with its accelerometer measurements have also provided new insight into air density and wind speeds in the upper atmosphere.
On October 21, 2013 the mission came to a natural end when it ran out of fuel. Over the past three weeks the satellite gradually descended.
While most of the 1,100 kg satellite disintegrated in the atmosphere, an estimated 25% reached Earth's surface.
Herschel Space Observatory (Launched on May 14, 2009. About sixty days after launch Herschel reached its orbit around L2. For reasons of cost effectiveness, ESA decided to launch Herschel together with Planck, a mission to study the cosmic microwave background radiation. The two spacecraft separated soon after launch and are being operated independently.
The European Space Agency's Herschel Space Observatory (formerly called Far Infrared and Sub-millimetre Telescope or FIRST) has the largest single mirror ever built for a space telescope. At 3.5-metres in diameter, the mirror will collect long-wavelength radiation from some of the coldest and most distant objects in the Universe. In addition, Herschel is the only space observatory to cover a spectral range from the far infrared to sub-millimetre.
Herschel's operational orbit is located 1.5 million kilometres away from the Earth in a direction diametrically opposite the Sun, at the second Lagrange point of the Sun-Earth system (L2). There the spacecraft is in a Lissajous orbit around L2 with an average amplitude of about 700,000 km and an orbital period of about 178 days.
Herschel completed its science observations on April 29, 2013.
The main manoeuvre in a series to boost the spacecraft from its operational orbit around L2 of the Sun-Earth system and into its final heliocentric orbit was successfully performed, on May 13-14, 2013.
Herschel's long and successful lifetime of scientific observations has come to an end. On April 29, 2013, the spacecraft ran out of liquid helium coolant required to maintain the operational temperatures for the instruments' detectors.
On June 17, 2013, Herschel operations were concluded, following the last manoeuvre to deplete the spacecraft's fuel and the final passivation of the spacecraft. Herschel has been switched off and is in its final heliocentric orbit. The mission is now in its post-operations phase)
Planck Space Telescope (ESA & NASA. Launched in May 14, 2009. The Cosmic Microwave Background (CMB) preserves a picture of the Universe as it was about 380,000 years after the Big Bang, and can reveal the initial conditions for the evolution of the Universe. Planck's main objective is to measure the fluctuations of the CMB with an accuracy set by fundamental astrophysical limits. The spacecraft will chart the most accurate maps yet of the CMB.
Planck's instrument detectors are so sensitive that temperature variations of a few millionths of a degree will be distinguishable. This unrivalled sensitivity together with the large and smooth surface of its telescope and its unprecedented wavelength coverage make Planck the most sophisticated 'time machine' ever)
Planck reveals an almost perfect Universe (March 21, 2013: Acquired by ESA's Planck space telescope, the most detailed map ever created of the cosmic microwave background - the relic radiation from the Big Bang - was released today, revealing the existence of features that challenge the foundations of our current understanding of the Universe. The image is based on the initial 15.5 months of data from Planck and is the mission's first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380,000 years old.
At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2,700ºC. When the protons and electrons joined to form hydrogen atoms, the light was set free. As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero. This 'cosmic microwave background' - CMB - shows tiny temperature fluctuations that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today. According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before. By analysing the nature and distribution of the seeds in Planck's CMB image, we can determine the composition and evolution of the Universe from its birth to the present day. Overall, the information extracted from Planck's new map provides an excellent confirmation of the standard model of cosmology at an unprecedented accuracy, setting a new benchmark in our manifest of the contents of the Universe. But because precision of Planck's map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood. One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model - their signals are not as strong as expected from the smaller scale structure revealed by Planck. Another is an asymmetry in the average temperatures on opposite hemispheres of the sky. This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look. Furthermore, a cold spot extends over a patch of sky that is much larger than expected. The asymmetry and the cold spot had already been hinted at with Planck's predecessor, NASA's WMAP mission, but were largely ignored because of lingering doubts about their cosmic origin. One way to explain the anomalies is to propose that the Universe is in fact not the same in all directions on a larger scale than we can observe. In this scenario, the light rays from the CMB may have taken a more complicated route through the Universe than previously understood, resulting in some of the unusual patterns observed today.
Beyond the anomalies, however, the Planck data conform spectacularly well to the expectations of a rather simple model of the Universe, allowing scientists to extract the most refined values yet for its ingredients. Normal matter that makes up stars and galaxies contributes just 4.9% of the mass/energy density of the Universe. Dark matter, which has thus far only been detected indirectly by its gravitational influence, makes up 26.8%, nearly a fifth more than the previous estimate. Conversely, dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for less than previously thought. Finally, the Planck data also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant. At 67.15 kilometres per second per megaparsec, this is significantly less than the current standard value in astronomy. The data imply that the age of the Universe is 13.82 billion years)
SMART-1 Moon Mission (Launched in September 27, 2003. Arrived in Lunar orbit on November 15, 2004. SMART-1 was the first European spacecraft to travel to and orbit around the Moon. This was only the second time that ion propulsion has been used as a mission's primary propulsion system (the first was NASA's Deep Space 1 probe launched in October 1998). After having conducted Lunar orbit science operations, its mission ended through Lunar impact on September 3, 2006. Testing solar-electric propulsion and other deep-space technologies, and making Lunar scientific investigations. SMART stands for Small Missions for Advanced Research in Technology. SMART-1 looked for water (in the form of ice) on the Moon. It travelled to the Moon using solar-electric propulsion and carrying a battery of miniaturised instruments. As well as testing new technology, SMART-1 did the first comprehensive inventory of key chemical elements in the Lunar surface. It also investigated the theory that the Moon was formed following the violent collision of a smaller planet with Earth, four and a half thousand million years ago)
Rosetta Mission - Comet 67P/Churyumov-Gerasimenko Explorer (Orbiter and lander. ESA's Rosetta mission was launched on March 2, 2004, for an operational mission of 12 years. It spent ten years in space and reached periodic (6.5 years) Comet 67P/Churyumov-Gerasimenko on May 2014. Over the next six months, it edged closer to the black, dormant irregular nucleus, roughly 3 x 5 km across, until it was only some 25 kilometres away.
During a circuitous ten-year trek across the Solar System, Rosetta crossed the asteroid belt twice and gained velocity from gravitational 'kicks' provided by close fly-bys of Mars (February 25, 2007) and Earth (March 4, 2005, November 13, 2007, and November 13, 2009). It later traveled into deep space, more than five times Earth's distance from the Sun.
The Rosetta orbiter arrived on August 6, 2014 at Comet 67P/Churyumov-Gerasimenko (3.5 AU from the Sun) and for a year remained in close proximity to the icy nucleus, mapping its surface and studying changes in its activity, as it plunges towards the warmer inner reaches of the Sun's domain.
On 12 November 2014, 09:03 GMT, a small lander, called Philae, was released onto the surface of this mysterious cosmic iceberg. On 12 November 2014, 16:03 GMT, ESA's Rosetta mission has soft-landed its Philae probe on the comet, the first time in history that such an extraordinary feat has been achieved. On 14 November 2014 Philae was in trouble due to the final landing locatiom (it bounced off twice), near a cliff that partially shades the solar panels. On 15 November 2014 the lander returned all of its housekeeping data, as well as science data from the targeted instruments. This completed the measurements planned for the final block of experiments on the surface. On 19 November 2014 with the Philae lander's mission complete, Rosetta will now continue its own extraordinary exploration, orbiting Comet 67P/Churymov-Gerasimenko during the coming year as the enigmatic body arcs ever closer to our Sun.
More than a year will pass before the remarkable mission draws to a close in December 2015. By then, both the spacecraft and the comet will have circled the Sun and be on their way out of the inner Solar System. Scientists will be eagerly waiting to compare Rosetta's results with previous studies by ESA's Giotto spacecraft and by ground-based observatories. These have shown that comets contain complex organic molecules - compounds that are rich in carbon, hydrogen, oxygen and nitrogen. Intriguingly, these are the elements which make up nucleic acids and amino acids, the essential ingredients for life as we know it. Did life on Earth begin with the help of comet seeding? Rosetta may help us to find the answer to this fundamental question)
Venus Express (Launched on November 9, 2005, arrived at Venus on April 11, 2006. It has been orbiting Venus in an elliptical 24-hour loop that takes it from a distant 66,000 km over the south pole - affording incredible global views - to an altitude of around 250 km above the surface at the north pole, close to the top of the planet's atmosphere.
With a suite of seven instruments, the spacecraft has provided a comprehensive study of the ionosphere, atmosphere and surface of Venus.
Venus has a surface temperature of over 450°C, far hotter than a normal kitchen oven, and an extremely dense, choking mixture of noxious gases for an atmosphere. But from the mission's infrared survey of the chemical composition of the rocky surface, we have learned that Venus might have once had a plate tectonics system like Earth, and even an ocean of water.
Just like Earth, Venus is losing parts of its upper atmosphere to space and Venus Express measured twice as many hydrogen atoms escaping out of the atmosphere than oxygen. Because water is made of two hydrogen atoms and one oxygen atom, the observed escape indicates that water is being broken up in the atmosphere.
Meanwhile, the spacecraft's cameras have tracked thousands of features in the cloud tops some 70 km above the planet's surface, including an enormous swirling vortex at the planet's south pole that shares similarities with hurricanes on Earth. The spacecraft also recorded bursts of lightning - identified by their electromagnetic signature - generated in clouds of sulphuric acid.
Studies of the planet's 'super-rotating' atmosphere - it whips around the planet in just four Earth-days, much faster than the 243 days the planet takes to complete one rotation about its axis - also turned up some intriguing surprises. In one study, average wind speeds were found to have increased from roughly 300 km/h to 400 km/h over a period of six Earth years. Conversely, a separate study found that the rotation of the planet had slowed by 6.5 minutes since NASA's Magellan, which completed its 5-year mission at Venus 20 years ago, measured it. However, it remains unknown if there is a relationship between the increasing wind speeds and the slowing rotation.
Magellan's radar survey of the planet revealed that its surface was heavily altered in the past by a large number of volcanoes. But Venus Express has provided tantalising hints that the planet may well be still geologically active today. One study found numerous lava flows that must have been created no more than 2.5 million years ago, just yesterday on geological timescales, and perhaps much more recently. Indeed, measurements of sulphur dioxide in the upper atmosphere have shown large variations over the course of the mission. Although peculiarities in the atmospheric circulation may produce a similar result, it is the most convincing argument to date of present-day active volcanism.
On May 16, 2014, after eight years in orbit, the fuel supplies necessary to maintain the elliptical orbit are running low and will soon be exhausted. Thus, routine science operations concluded this week, and the spacecraft is being prepared for one final mission: to make a controlled plunge deeper into the atmosphere than ever before attempted.
This 'experimental aerobraking' phase is planned for June 18 - July 11, 2014, during which time some limited science measurements with the spacecraft's magnetic field, solar wind and atom analysing instruments will be possible. Also, temperature and pressure sensors will record the conditions that the spacecraft is experiencing.
It is possible that the remaining fuel in Venus Express will be exhausted during this phase or that the spacecraft does not survive these risky operations. But if the spacecraft is still healthy afterwards, its orbit will be raised again and limited operations will continue for several more months, fuel permitting. However, by the end of the year, it is likely that Venus Express will have made its final descent into the atmosphere of the planet, bringing a fantastic scientific endeavour to an end)
Observing the Earth (The single location where we can learn the most about our planet is found nowhere on Earth but high up above it. Earth Observation images show the world through a wide-enough frame so that complete large-scale phenomena can be observed to an accuracy and entirety it would take an army of ground-level observers to match)
CryoSat (Launched on April 8, 2010. Measuring the thickness of polar sea ice and monitoring changes in the ice sheets that blanket Greenland and Antarctica. The satellite flies in a low Earth, polar, non-Sun-synchronous orbit at a mean altitude of 717 km, reaching latitudes of 88° north and south, to maximise its coverage of the poles.
The main data product is the 'Level-2' product, sometimes called the Geophysical Data Record. This contains the surface elevation along the ground track together with all auxiliary data needed to fully exploit these measurements.
Satellite records show a constant downward trend in the area covered by Arctic sea ice during all seasons, in particular in summer, with the minimum recorded occurring in the autumn of 2012. In October 2013, however, CryoSat measured about 9,000 cubic km of sea ice - a notable increase compared to 6,000 cubic km in October 2012)
Gaia (A global space astrometry mission, Gaia will make the largest, most precise three-dimensional map of our Galaxy by surveying more than a thousand million stars. Launched on December 19, 2013. Gaia took about a month to cruise to its orbit around the Lagrangian point known as L2. This gravitationally balanced location, 1.5 million km further from the Sun than Earth, keeps pace with Earth's yearly revolution around the Sun and thus maintains the positions of the Sun, Earth and spacecraft on a single line. The spacecraft will orbit in a so-called Lissajous orbit around L2, once every 180 days. During its five-year mission, the spacecraft spins slowly, sweeping its two telescopes across the entire celestial sphere. As the detectors repeatedly measure the position of each celestial object, they will detect any changes in the object's motion through space.
After launch, Gaia will unfold a 'skirt' just over 10 m in diameter. This will act as both a sunshade to permanently shade the telescopes and allow their temperatures to drop to below -100°C, and as a power generator for the spacecraft. The underside of the shield is partially covered with solar panels and will always be facing the Sun, generating electricity to operate the spacecraft and its instruments.
Gaia has its roots in ESA's Hipparcos mission (1989-1993), which catalogued more than 100,000 stars to high precision, and more than a million to lesser precision. Now, some 20 years later, Gaia will launch on its mission to catalogue a thousand million stars, measuring each star's position and motion 200 times more accurately than Hipparcos, and producing 10,000 times more data than its predecessor)

Students for the Exploration and Development of Space (SEDS):
SEDS Home Page (SEDS is an independent, student-based organization which promotes the exploration and development of space. Founded in 1980)
Bill Arnett's Web Sites (Site map for nineplanetes.org. A Multimedia Tour of the Solar System: describes the history, mythology and current scientific knowledge of each of the planets and moons and other objects in our solar system)
Herschel 400 list (This directory contains two lists of Herschel objects)
Large Telescopes (The World's Largest Optical Telescopes. Bill Arnett)
More Astronomy and Space Links (Hartmut Frommert, Christine Kronberg)
Orbiting Astronomical Observatories (Since the early years of spaceflight, the advantages of astronomical observing above the Earth's atmosphere were recognized, and led to the introduction of astronomical instruments on spacecraft, i.e., astronomical observatories in space. Hartmut Frommert)
Spider's Homepage (Hartmut Frommert)
The Discovery of the Deep Sky Objects (Since the earliest times, humans could view stars at night whenever it happened not to be cloudy. As in prehistoric times, there was barely no light polution in most regions of Earth, our ancestors could view stars of very faint light, and thus some of those objects we now summarize as Deep Sky Objects. This way, some of these objects are known as long as anything is known. Hartmut Frommert, Christine Kronberg)
The Interactive NGC Catalog Online (This is the interactive NGC (and IC, and Messier) catalog at SEDS, based on the famous NGC 2000.0 by R.W. Sinnott of Sky Publishing Corp., who also created the electronic version used by this online service. Hartmut Frommert)
The Messier Catalog (During the years from 1758 to 1782 Charles Messier, a French astronomer (1730 - 1817), compiled a list of approximately 100 diffuse objects that were difficult to distinguish from comets through the telescopes of the day. Discovering comets was the way to make a name for yourself in astronomy in the 18th century - Messier's first aim was to catalog the objects that were often mistaken for comets.
Fortunately for us, the Messier Catalog became well known for a much higher purpose, as a collection of the most beautiful objects in the sky including nebulae, star clusters, and galaxies.
The purpose of these web pages is to provide a complete guide to the 110 objects recognized as the standard Messier catalog. More importantly, we would like to generate interest in astronomy, the night sky and the universe beyond us, and to encourage a sense of wonder and exploration. We also hope that these pages may be useful as a reference for amateur astronomers. Hartmut Frommert)
The Nine Planets (This website is an overview of the history, mythology, and current scientific knowledge of the planets, moons and other objects in our Solar System. Each page has our text and NASA's images, some have sounds and movies, most provide references to additional related information. Bill Arnett)
The Nine Planets For Kids (With permission from Bill Arnett, I've revamped his web site, The Nine Planets, for younger audience suitability (upper elementary grades). The Nine Planets is a very comprehensive information site featuring the planets of our solar system (related items included). To create a simpler, more focused atmosphere, I've eliminated the more advanced concepts, emphasized the more basic concepts, and given it more of a 'kid-friendly' look-and-feel)

Astronomical World-Wide Web Indexes (Índices Astronómicos en el World-Wide Web):

Astronomy in Latin America (LANIC) (University of Texas at Austin)
Astronomy Links (Astronomy and Space Related Links from Around the World)
Astro Web Astronomical Internet Resources, AstroWeb Consortium
Open Directory Project: Top: Science: Astronomy
Open Directory Project: World: Español: Ciencia y tecnología: Astronomía (en Castellano)

Astronomy Equipment (Equipo Astronómico):

Information (Información):
About Daylight Saving Time (DST) (Web Exhibits: History, rationale, laws & dates)
Astronomy Notes (Astronomy, Introductory college-level course by Nick Strobel, Bakersfield College)
AutoStarSuite.Net (Your Source for Meade AutoStar, AutoStarSuite, LPI, and DSI information)
Calendars through the Ages (Web Exhibits: Calendars)
 - De revolutionibus orbium coelestium (Nicholas Copernicus, 1543)
 - Dialogue Concerning the Two Chief World Systems (Galileo Galilei, 1632)
CalSKY - The Calculated Sky On-line Configurable Astronomical and Space Calendar
Catching the Light (by Jerry Lodriguss)
 - Astrophotography Techniques
 - Digital Processing Techniques
Digital Imaging with Richard Berry
Digital Photography Review
Geographic Names Server (GNS) (NGA Geographic Names Data: Coordinates)
Google Earth (On-line Topographic Map of the Earth and Sky, Free Download)
Google Mars (On-line Elevation, Visible and Infrared Maps of Mars, Free)
Google Moon (On-line Elevation, Visible and Human Maps of the Moon, Free)
Harvard-Smithsonian Center for Astrophysics (CfA) (Harvard College Observatory (HCO) and Smithsonian Astrophysical Observatory (SAO))
Heavens-Above (Sky and Satellite Visibility. Developed and maintained by Chris Peat. Free)
Historical Physics Teaching Apparatus (Thomas B. Greenslade, Jr.)
Ian Ridpath's Star Tales (Constellation Mythology)
International Meteor Organization (IMO) (Calendarios de Lluvias de Meteoros)
Internet Encyclopedia of Philosophy (IEP) (Detailed information on key topics and philosophers)
Introduction to Geomag (USGS)
Journal of Cosmology (Rudolf Schild, Executive Editor, Center for Astrophysics, Harvard-Smithsonian)
Khan Academy (A free world-class education for anyone anywhere)
Lewis Learning (Video and animation based curriculum resources)
Magnetic Declination Calculator (Natural Resources Canada)
MetEd (Meteorology Education & Trainning - Free - Con algunos módulos también en Castellano)
Navigator Software (Omar Reis)
 - The Online Nautical Almanac ("Nautical Almanac" daily pages: 1950 to 2050)
Neave Planetarium (Browser Planetarium, Neave Interactive, Paul Neave)
Philosophiae Naturalis Principia Mathematica by Sir Isaac Newton (Project Gutenberg - Free ebooks)
Ocean World (Oceanography in the 21st Century, Texas A&M University)
Online Astronomy Text (Courtney Seligman, Professor of Astronomy, Long Beach City College, California)
Project CLEA (Contemporary Laboratory Experiences in Astronomy)
Science@NASA Headline News (Author | Production editor: Dr. Tony Phillips)
 - Ciencia@NASA (Historias sobre ciencia de la NASA en Castellano)
SFA Star Charts (Dan Bruton, SFA Observatory. Mag. 5 + Messier Catalog objects, .pdf)
Sky & Telescope: How To - Astronomy Basics
Sky & Telescope: Observing Highlights
Sky & Telescope: Observing - Interactive Observing Tools
 - Sky & Telescope: Observing - Almanac v3.0
Sky & Telescope: Observing - Interactive Sky Chart
Skyhound (Greg Crinklaw, SkyTools 3 Astronomical Software)
SkyMaps.com (Free monthly sky maps and calendar)
SkyView (The Internet's Virtual Telescope)
StarDate Online - Your Guide to the Universe (McDonald Observatory, University of Texas)
The Astro Philes (Supplementary Resources for SJSU Astronomy Courses, Les Tomley, Sán José State University)
The Galileo Project (Life and work of Galileo Galilei (1564-1642). Rice University)
The Night Sky This Week (Information about the night sky and articles on astronomical topics. Emil Neata)
The Physics Factbook (An encyclopedia of scientific essays. Glenn Elert)
The Physics Hypertextbook (A work in progress. Glenn Elert)
The Resilient Earth (.pdf Downloadable Book. Doug L. Hoffman & Allen Simmons, 2008 - Free)
The Worlds of David Darling (Space & Science News)
 - The Internet Encyclopedia of Science
 - Encyclopedia of Renewable Energy and Sustainable Living
Timothy Ferris (Seeing in the Dark, The Whole Shebang, Coming of Age in the Milky Way)
Universo Online - Su Guía para el Universo (Observatorio McDonald de la Universidad de Texas, en Castellano)

Hardware:
Anacortes Telescope & Wild Bird (High end optics and sport optics along with outdoor gear and birding supplies)
 - Astromart (Astronomy classifieds, articles, reviews and more)
Astronomics (Telescopes and Telescope Accessories. Since 1979)
 - Cloudy Nights (A forum for reviews of telescopes and accessories)
Astronomy-Mall (Products and Services. Free Astronomy Classifieds)
Binoculars.com (Binoculars, Telescopes, Spotting Scopes)
Bonney Lake Astro Works (Quality Telescope Accessories. Milburn Telescope Wedges and Dovetail Rail Systems)
Celestron (Telescopes, Microscopes, Binoculars and Accesories)
Company Seven - Astro-Optics Division (Telescopes and Accesories, Information. Since 1980)
DayStar Filters (Ultra-narrow Bandpass Filters, Solar Telescopes)
Deep Space Products (HyperTune products, Telescopes, Accessories, Custom Services. Founded in 2007)
Edmund Scientifics (Astroscan Telescope, etc. Since 1942)
Edmund Optics (Imaging - Photonics - Optomechanics - Lasers. Since 1942)
Fishcamp Engineering (Starfish Astro-camera/Auto-guider. Founded in January 1, 1989)
Focus-Camera (Camera Shop | Video & Digital Cameras, Lenses & More. Since 1966)
Garmin (Global Positioning Systems (GPS). Incorporated in July 2000)
JMI Telescopes (Astronomical Telescopes and Aftermarket Telescope Accessories. Jim Burr. Since December 31, 1990)
Kendrick Astro Instruments (Dew Removal, Imaging Power, Power Packs, Observer Tents, Solar Filters, Focus Masks, USB Hubs)
Losmandy Astronomical Products (Precision Equatorial Mounts and Secondary Systems. Since 1981)
MAG1 Instruments (PortaBall Telescopes)
Magellan GPS (Consumer Navigation Systems & Accessories. Founded in 1986)
Meade Instruments (Telescopes, Binoculars, Weather Stations. Founded in 1972)
 - Coronado Solar - Products (H-alpha filters, Personal Solar Telescopes)
Murnaghan Instruments (e-Scopes, Odyssey Telescopes. Equipment and accessories. Coulter Optical)
Oceanside Photo & Telescope (OPT) (Astronomy Telescopes, Accessories, CCD and Digital Cameras)
Omega Filters (Amateur Astronomy Filters from a Supplier of the Hubble Space Telescope. Formed in January 1, 1969)
Orion Telescopes & Binoculars (Telescopes, Binoculars and Accesories. Since 1975)
PreciseParts (Precision custom adapters and one-of-a-kind telescope accessories. Design your own custom adapter online in a few clicks with Build-An-Adapter, our Online Adapter Builder)
Rigel Systems (Manufacturer of innovative astronomy accessories. QuikFinder Compact Reflex Sight and other accessories)
Santa Barbara Instrument Group (SBIG) (Thermoelectrically cooled CCD imaging cameras and accessories, filters and filter wheels)
Scopestuff (Telescope Accesories and Hardware)
Supercircuits Inc. Americas (Video cameras. Since 1989)
Surveillance Video (Home Security Cameras, Surveillance Cameras, Security Camera Systems, Since 1971)
Teleport Telescopes (The Telescoping Telescope. Portable Dobsonian Telescopes. From 2002 to 2011. Tom Noe)
Telescopes.com (Telescopes, binoculars and accesories)
Tele Vue Optics (Telescopes, eyepieces, accesories. Since 1979. Al Nagler, founder)
Thousand Oaks Optical (Solar, Nebular and H-Alpha Filters, Solar Eclipse Viewers, Dew Heaters)
Vixen (Astronomical Telescopes and mounts, Binoculars, Field Scopes, Microscopes, Magnifiers, Compasses, CCD Cameras. Founded in 1949)
William Optics USA (Short-tube, Highly-portable Refractor Telescopes, Diagonals, Prisms, Eyepieces, Digital Camera Adapter Lenses, Accesories, Binoculars. Founded in 2000)

Software:
Aberrator (Star-Test Image Simulator, Freeware, MS Windows)
Adobe Acrobat Reader (Freeware .pdf format reader)
alcyone astronomical software (Free Planetary, Lunar, and Stellar Visibility calculator)
ASCOM - Standards for Astronomy (Free ASCOM Platform and Drivers)
Astroart Astronomical Images Processing and Analysis, by Fabio Cavicchio and Martino Nicolini. (MS Windows)
AstroPlanner Astronomical Planning & Logging Software (MS Windows and Macintosh, with Free version)
BlackFrame NR Noise reduction using Black frame method, Mediachance Freeware (MS Windows)
Computer Aided Astronomy (C2A) Planetarium software, Freeware (MS Windows)
Cartes du Ciel - Sky Charts Free Astronomy software, Planetarium & Celestial atlas (MS Windows, Patrick Chevalley, English version, versión en Castellano)
Celestia (Free real-time space simulation for Windows, Linux, and Mac OS X)
Celestrak NORAD Two-Line Satellite Elements Sets. Freeware by Dr. TS Kelso.
Cielo e Terra "Sky Draw - Mappa del Cielo", "Earth Map - Mappa della Terra", "Eclipses & Earth - Eclisse e Terra", "Planetarium - Planetario", by Piero Massimino, CAO. (On-line Freeware, and MS Windows)
CyberSky Planetarium program (MS Windows)
DeepSky Astronomy Software, by Steve Tuma. (MS Windows CD)
DeepSkyStacker Registering, Stacking. Freeware (MS Windows, con versión en Castellano)
Distant Suns Planetarium program, by Mike Smithwick (MS Windows, iOS, Android, Kindle, Nook)
Deep Space Planetarium program, David Chandler Company. (MS DOS)
GIMP The GNU Image Manipulation Program. Freeware (GNU/Linux, Mac OS X, Windows)
Hallo northern sky (HNSKY) Planetarium program with 10,607 deepsky objects and all stars to magnitude 12, and with the original GSC CD-ROM's, GSC-ACT or the USNO to magnitude 15 or more. Displays all planets, the Moon, Sun, moons of Saturn and Jupiter, Mars, Uranus and Neptune and a few hunderd asteroids and comets. By Han Kleijn. Freeware (MS Windows)
Home Planet Comprehensive Astronomy Software Package. Freeware (John Walker, MS Windows)
Intricate Micro Systems (Win245, CB245 Cookbook Camera Image Acquisition software)
Mars Previewer II Calcula las efemérides físicas de Marte y muestra una imagen realista del planeta. Calculates Mars physical ephemeris and draws a realistic image of the planet. Freeware by Leandro Ríos. (3 MB, MS Windows)
MAXCLOCK Free High-precision digital astronomical software clock. Udo Mark (MS DOS/Windows).
MyStars! (Relativedata Inc, MS Windows on-line planetarium software)
Occult Free Occultation Calculations software (Dave Herald, IOTA. MS Windows)
PhET (Free online physics, chemistry, biology, earth science and math simulations)
Planetarium Software (Bill Arnett)
Previsions for the ISS, the HST for the next 10 days Satellites Observation, by Alphonse Pouplier. (On-line Freeware, and MS DOS)
Project Pluto 'Guide' planetarium program (MS DOS & Windows, CD-ROM)
Radio-Sky Sidereal Clock (Freeware, MS Windows)
RegiStar (Automatic image registration for astrophotography, MS Windows)
Registax (Automatic image registration for astrophotography, Freeware, MS Windows)
Satellite tracking with GPS Varol Ocan (MS Windows)
SkyMap Star charting software for astronomers (MS Windows)
Sky Tools (PC-Sky, MS Windows, CD-ROM)
SkyView (The Internet's Virtual Telescope, NASA)
Software Bisque TheSky planetarium program (MS Windows, CD-ROM)
StarCalc Astronomy planetarium & star mapping program by Alexander Zavalishin. Freeware (MS Windows)
Starry Night Planetarium program, Sienna Software (MS Windows or Macintosh)
Stellarium (Free open source planetarium for your computer, by Fabien Chereau et al.)
 - ASCOM Initiative (Free Interface Standards and astronomical instrument drivers)
 - StellariumScope (Free Telescope Control, Welsh Dragon Computing)
Sundials Shadows - Design sundials and astrolabes (Française/English) François Blateyron. Freeware (MS Windows)
SunGraph Graphical Sun Ephemerides - Bob Urschel. Freeware (MS Windows and Macintosh)
The Earth Centered Universe (ECU) (Nova Astronomics, MS Windows)
UnitJuggler unit converter Free (Pierre Di Marco, Online Application)
Virtual Moon Atlas Free Astronomy software, Moon observation or survey (MS Windows, Patrick Chevalley, Christian Legrand, English version, versión en Castellano)
WinStars Shareware planetarium software (MS Windows, Franck Richard)
Wolfram|Alpha (Computational Knowledge Engine)
World Wind (NASA - Free Topographic Satellite Map of the Earth, Moon, Venus, Mars, Jupiter and the sky)
WXTide32 (Free Windows tide and current prediction program)

Other Astronomy and Astrobiology Web Sites (Otros sitios de Astronomía y Astrobiología en el Web):

25 Years of Voyager: An Epic Jouney (Unraveling the Secrets of the Solar Wind, Voyager discoveries. University of California Riverside Space Physics. Voyager was launched in 1977)
3-D Star Maps (Science & Science Fiction. Winchell Dosuk Chung)

Abrams Planetarium (Michigan State University)
 - Night Sky Notes (What's up in the sky)
Active Cavity Radiometer Irradiance Monitor (ACRIM) (Total Solar Irradiance (TSI) Monitoring)
Adler Planetarium and Astronomy Museum (Chicago)
Advanced Composition Explorer (ACE) (Sampling of low-energy particles of Solar origin and high-energy Galactic particles. August 25, 1997)
Aeronomy of Ice in the Mesosphere (AIM) (Satellite Exploration of Polar Mesospheric Clouds - Noctilucent Clouds)
Airbus Defence and Space: Geo-Intelligence (SPOT Satellites Imagery & Maps, Geospatial Services, Geoinformation Products, Elevation data & 3D)
Alan Kostelecky (Standard-Model Extension (SME) - Background information on Lorentz/CPT Violation)
Albert Einstein - Image and Impact (American Institute of Physics History Center exhibit)
 - Albert Einstein - Imagen e Impacto (Traducido al Castellano)
Albert Einstein Online (S. Morgan Friedman)
American Association of Amateur Astronomers (AAAA) (since 1996)
American Association of Variable Star Observers (AAVSO)
American Astronomical Society (AAS) (since 1899)
Amateur Astronomers Association of New York City (AAA) (organized in 1927)
American Institute of Mathematics (AIM) (established in 1994)
American Institute of Physics (AIP) (to advance, promote and serve the physical sciences for the benefit of humanity)
American Mathematical Society (AMS) (founded in 1888)
American Physical Society (APS) (founded on May 20, 1899)
American Satellites Orbital Data at AMSAT (Space Shuttle Orbital State Vectors and Keplerian Elements)
Analemma (The figure-8 path that the Sun makes in the sky. Bob Urschel)
Apache Point Observatory (Astrophysical Research Consortium 3.5 m Telescope, 2.5 m Sloan Foundation Telescope, New Mexico State University 1.0 m Telescope, Astrophysical Research Consortium Small Aperture Telescope (ARCSAT). 0.5 m (or 20") Telescope)
 - APOLLO (Lunar Laser-ranging Operation to measure the round-trip travel time of laser pulses bounced off the Lunar retroreflectors)
Apollo Image Archive (Online digital archive of the original Apollo flight films. Johnson Space Center. Arizona State University)
Archaeoastronomy (Spotlights the dawn of human history. Pinpoints equinox, solstice and cross quarter moments throughout the year)
Archives of Electronic Publishing in Science (arXiv) (Cornell University Library, Los Alamos National Laboratory)
Arecibo Observatory (the world's largest single-dish radio telescope. National Astronomy and Ionosphere Center, NSF, Cornell University)
Arkansas Sky Observatories - ASO - (Astronomical Observatories) (Fournier Lunar Atlas)
Arqueoastronomía (Dedicado a la difusión de la Arqueoastronomía en Hispanoamérica)
Artemis Project (Privately financed commercial venture for a permanent, manned Lunar base)
Association of Universities for Research in Astronomy (AURA) (a consortium of 39 US institutions and 6 international affiliates that operates world-class astronomical observatories)
Association of Lunar and Planetary Observers (ALPO) (to study the Sun, Moon, planets, asteroids, meteors, and comets)
Asteroid Occultation Predictions (Steve Preston)
Astrobiology Magazine (Exploring the Solar System and beyond)
Astronomers Without Borders (one People, One Sky. A global astronomy community)
 - The World At Night (TWAN) (Sky and Landscape Photographs)
Astronomical League (To Promote the Science of Astronomy)
Astronomical Society of the Pacific (fosters scientific curiosity, advances science literacy, and shares the excitement of exploration and discovery)
Astronomy & Astrophysics (A&A) (An International Weekly Journal. Open Access)
Astronomy Boy (Resources & Tutorials for Amateur Astronomers. By Jeff DeTray)
Astronomy Cafe (Ask the Astronomer, Dr. Sten Odenwald)
Astronomy Links (OPT Telescopes Astronomy and Space Directory, Related Links from Around the World)
Astronomy Magazine (Interactive Star Charts, Planets, Meteors, Comets, Telescopes)
Astronomy Notes (Introductory college-level course by Nick Strobel, Bakersfield College, California)
Astronomy to Go (Bob Summerfield, The Yard Scope)
Astrophotography by Jim Ferreira (High Resolution Solar, Lunar, Planetary & Deep Sky CCD Astrophotography)
Astrophotography by Tom Matheson
Astro Web (Astronomy on the Internet - Resources. Discontinued on 10 July 2010)
A Universe in Time (Images and Resources in Astronomy - Present & Historical. By Ken Pinkela)
Aurora's Northern Lights (Images of the Aurora Borealis. By Jan Curtis)
A Walk Through Time (The Evolution of Time Measurement through the Ages. National Institute of Standards and Technology - NIST)

Bartol Neutron Monitors (Cosmic ray monitors. University of Delaware, Bartol Research Institute)
Berkeley Cosmology Group (from cosmological probes of fundamental physics to the formation and evolution of galaxies and large scale structure)
Berkeley Open Infrastructure for Network Computing (BOINC) (Volunteer and Grid Computing: SETI@home, etc.)
Big Bear Solar Observatory (BBSO) (New Jersey Institute of Technology - NJIT)
Bing Maps (Microsoft Virtual Earth)
Blind Watchmaker Applet (Mark Jones, an algorithm conceived by Richard Dawkins to demonstrate how random mutation followed by non-random selection can lead to interesting, complex forms)
Botany online - The Internet Hypertextbook (Alice Bergfeld - Rolf Bergmann - Peter v. Sengbusch, 1996 - 2004. University of Hamburg)
BOOMERANG (Balloon Observations Of Millimetric Extragalactic Radiation ANd Geophysics)
(To map the Cosmic Microwave Background (CMB). Over Antarctica in 1998 and 2003)
Boonhill Amateur Astronomy (Greater Michigan astronomical community, Douglas Bock)

California Institute of Technology Infrared Processing & Analysis Center (IPAC) (dedicated to astronomy and planetary science missions, with a special emphasis on infrared-submillimeter astronomy and exoplanet science. California Institute of Technology (Caltech), Pasadena, Calif)
Cassini Imaging (CICLOPS) (Official Source of Cassini images of Saturn, its rings & moons)
Catching the Light (Astrophotography, Jerry Lodriguss)
Center for Archaeoastronomy (founded at the University of Maryland in 1978)
Center for Backyard Astrophysics (CBA) (A global network of small telescopes dedicated to photometry of cataclysmic variables - Columbia University)
Center for Environmental Biotechnology (CEB) (The University of Tennessee, Knoxville)
Center For Southeastern Tropical Advanced Remote Sensing (CSTARS) (University of Miami Rosenstiel School of Marine and Atmospheric Science (RSMAS), Virginia Key, Florida)
Ceres: The Dwarf Planet
Chabot Space & Science Center (East Bay Area - Oakland CA)
Chandra X-Ray Observatory (Launched on July 23, 1999, to orbit at a distance from Earth ranging from 16,000 km (9,942 miles) to 133,000 km (about 82,646 miles), more than a third of the way to the Moon. The time to complete an orbit is 64 hours and 18 minutes)
Charles Darwin Foundation for the Galapagos (An international not-for-profit scientific organization. The CDF has been working in Galapagos since 1959 to ensure the conservation of Galapagos) (con versión en Español)
Chemical Elements.com - An Interactive Periodic Table of the Elements (by Yinon Bentor)
Classical Astronomy (A Visual Understanding of the Visible Sky, Jay Ryan)
ClearDarkSky (Clear Sky Charts for Canada, USA and parts of Mexico - Attilla Danko)
 - Clear Sky Alarm Clock (Mark Casazza)
Clementine Mission: 1994 - Complete map of the moon (Lunar Image Browser. Naval Research Laboratory - NRL)
Clementine - Mission Overview (Lunar and Planetary Institute - LPI)
ClimatePrediction.Net (BOINC distributed computing project to produce predictions of the Earth's climate)
Cloudbait Observatory (Colorado Rocky Mountains)
Clyde Tombaugh (1906-1997) (by Jeff Foust)
Cometography (Gary Kronk)
Computing Sun & Moon Transits by the International Space Station (Tom Fly)
Cool Cosmos (Your infrared guide to the world and the Universe beyond. IPAC - California Institute of Technology)
Cooperative Institute for Research in Environmental Sciences (CIRES) (University of Colorado at Boulder)
Cooperative Institute for Meteorological Satellite Studies (CIMSS) (University of Wisconsin - Madison)
 - Tropical Cyclones A Satellite Perspective
COsmic Background Explorer (COBE) Mission (at Lawrence Berkeley Laboratory)
Cosmic Microwave Background Radiation (Douglas Scott)
Cosmic Microwave Background Radiation, an Introduction (Wayne Hu)
Cosmic Microwave Background Astrophysics Research Program (UC Berkeley - Lawrence Berkeley National Laboratory, George Smoot)
Cosmology Tutorial (Ned Wright, Vice Chair for Astronomy, UCLA)
Cosmos in a Computer (One of the best cosmology sites in the Web,
part of NCSA's Multimedia Online Expo, Science for the Millennium,
a "pavilion" of the Internet 1996 World Exposition)

Dale Ireland's Astronomy Page (Dale Ireland)
Dark Skies Awareness: seeing in the dark (Measuring local levels of light pollution)
Dave Jurasevich's Images of the Universe (Astrophotography)
Dave Palmer's Astronomy Page (Dave Palmer)
Deep Impact (Mission to impact Comet Tempel 1 in July 4 '05, fly past Comet Hartley 2 in 2010, and observe Comet Garradd in 2012. Declared lost in Sep. 2013. University of Maryland)
Digital Sky LLD (Milky Way Panoramics)
Distributed Information Services for Climate and Ocean Products and Visualizations for Earth Research (DISCOVER)
 - Daily Earth Temperatures from Satellites (AMSU-A Temperatures, University of Alabama in Huntstville - UAH)
Dive and Discover - Expeditions to the Seafloor
Dr. James R. Webb (FIU Department of Physics)
Dynamical Astronomy JavaLab (Case Western Reserve University)

Earthquake Track (Map of Earthquakes Today)
EarthSky.org (Radio Series - A Clear Voice for Science)
Earth Science, Logistics, and Outreach Terrainbases (EarthSLOT)
Eclipse Chaser (Climatology and Maps for the Eclipse Chaser. Jeffrey R. Charles)
Eclipser (Weather and Map Files, Jay Anderson)
Edge Foundation Promoting inquiry into and discussion of intellectual, philosophical, artistic, and literary issues
 - The Third Culture (Beyond the Scientific Revolution, by John Brockman)
Einstein@Home [BOINC project for MS Windows, Macintosh, Linux, Android]
A scientific experiment that will harness the power of Internet-connected computers to search for spinning neutron stars (called pulsars) using data from the LIGO and GEO gravitational wave detectors.
Einstein Online (Explaining Einstein's theories of relativity to a general audience. English version, Max Planck Institute)
Elsevier (Science and health information, contains Open Access)
Encyclopedia.com (A collection of online encyclopedias, millions of free articles, pictures, facts, and biographies along with information about topics)
Encyclopedia Astronautica (History of Spaceflight)
Encyclopedia of Life (EOL) (Information and pictures of all species known to science)
Entropy and the Second Law of Thermodynamics (Frank L. Lambert, Professor Emeritus. Occidental College, Los Angeles)
Environmental Molecular Sciences Laboratory (EMSL) (William R. Wiley. Pacific Northwest National Laboratory. U.S. Department Of Energy, Office of Science)
Epoxi Mission (Mission to impact Comet Tempel 1 in July 4 '05, fly past Comet Hartley 2 in 2010, and observe Comet Garradd in 2012. Declared lost in Sep. 2013)
eSky: The Electronic Sky (A site dedicated to the entire universe)
 - Planet Wheel (a guide to the visibility of the planets in the sky)
European Centre for Medium-Range Weather Forecasts (ECMWF) (Deterministic medium-range forecast charts)
European Southern Observatory (ESO) La Silla, Paranal - Chile
 - New Technology Telescope (NTT) (The 3.58-metre New Technology Telescope (NTT) was inaugurated in 1989. It broke new ground for telescope engineering and design and was the first in the world to have a computer-controlled main mirror. The main mirror is flexible and its shape is actively adjusted during observations by actuators to preserve the optimal image quality. The secondary mirror position is also actively controlled in three directions. This technology, developed by ESO, known as active optics, is now applied to all major modern telescopes, such as the Very Large Telescope at Cerro Paranal and the future European Extremely Large Telescope)
 - Very Large Telescope (VLT) (The Very Large Telescope array (VLT) is the flagship facility for European ground-based astronomy at the beginning of the third Millennium. It is the world's most advanced optical instrument, consisting of four Unit Telescopes with main mirrors of 8.2m diameter and four movable 1.8m diameter Auxiliary Telescopes. The telescopes can work together, to form a giant 'interferometer', the ESO Very Large Telescope Interferometer, allowing astronomers to see details up to 25 times finer than with the individual telescopes. The light beams are combined in the VLTI using a complex system of mirrors in underground tunnels where the light paths must be kept equal to distances less than 1/1000 mm over a hundred metres)
 - European Extremely Large Telescope (E-ELT) (The European Extremely Large Telescope (E-ELT) is a revolutionary scientific project for a 40m-class telescope that will allow us to address many of the most pressing unsolved questions about our Universe. The E-ELT will be the largest optical/near-infrared telescope in the world and will gather 13 times more light than the largest optical telescopes existing today)
Exploratorium (The Exploratorium is a museum of science, art, and human perception located in San Francisco, California)

Far Ultraviolet Spectroscopic Explorer (FUSE) (Johns Hopkins University - NASA. Launched on June 24, 1999, and operated until October 18, 2008. (The Far Ultraviolet Spectroscopic Explorer (FUSE) was a NASA astrophysics satellite/telescope whose purpose was to explore the Universe using the technique of high-resolution spectroscopy in the far-ultraviolet spectral region)
Fermi National Accelerator Laboratory (Fermilab) (Fermilab is America's particle physics and accelerator laboratory)
 - Fermilab Center for Particle Astrophysics (FCPA) (What are we made of? How did the universe begin? What secrets do the smallest, most elemental particles of matter hold, and how can they help us understand the intricacies of space and time?
Since 1967, Fermilab has worked to answer these and other fundamental questions and enhance our understanding of everything we see around us. As the United States' premier particle physics laboratory, we work on the world's most advanced particle accelerators and dig down to the smallest building blocks of matter. We also probe the farthest reaches of the universe, seeking out the nature of dark matter and dark energy. The mission of the High Energy Physics program is to understand how our universe works at its most fundamental level. We do this by discovering the most elementary constituents of matter and energy, exploring the basic nature of space and time itself, and probing the interactions between them)
Focus Fusion Society (FFS) (Practical, Safe, Low-Cost Clean Energy, from Hydrogen & Boron by Nuclear Fusion. The goal for Focus Fusion, within reach in the next few years, is to reasearch, prototype and manufacture individual commercial fusion units (small enough to fit in a garage or shipping container) that are able to provide energy for a few thousand homes at least ten times cheaper than any known energy source)

Galaxy Evolution Explorer (GALEX) (Observing galaxies in ultraviolet light)
Gemini Observatory (Mauna Kea, Hawaii & Cerro Pachón, Chile)
GEO600 (Direct Detection of Gravitational Waves, Max Planck Institute for Gravitational Physics)
Gravity Probe B (Testing Einstein's Universe)
Gravity Recovery And Climate Experiment (GRACE) (Twin satellites launched in March 2002, are making detailed measurements of Earth's gravity field which will lead to discoveries about gravity and Earth's natural systems)
Grazing Occultation Events (United States/S. Canada/N. Mexico - Interactive Maps of Event Paths, Brad Timerson)
Great Circle Calculator (Javascript, Ed Williams)
Griffith Observatory (Griffith Observatory is an icon of Los Angeles, a national leader in public astronomy)

Hawaiian Astronomical Society
Helioseismic and Magnetic Imager for SDO
High Altitude Observatory (HAO) (Solar and Atmospheric Physics Research and Education)
High-Energy Transient Explorer 2 (HETE-2) (October 9, 2000. Detect and localize gamma-ray bursts. MIT)
High Resolution Imaging Science Experiment (HiRISE) (Exploring Mars in images, The University of Arizona)
 - HiRISE en español (Descubriendo Marte en imágenes)
Hobby-Eberly Telescope (HET) (The University of Texas at Austin)
Hubble Space Telescope Key Project on the Extragalactic Distance Scale (California Institute of Technology)
How Stuff Works (Marshall Brain)
HyperPhysics Concepts (Rod Nave, Georgia State University)

ICSTARS Astronomy (Vic Winter, Fred Bruenjes, Southern Skies Star Party [SSSP] - Titicaca, Bolivia)
Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) (March 25, 2000. Southwest Research Institute - SwRI)
Inconstant Moon (Multimedia tours of the Lunar surface)
Institute for Marine Remote Sensing (IMaRS) (University of South Florida)
International Astronomical Union (IAU)
 - CBAT/MPC/ICQ Index
 - Central Bureau for Astronomical Telegrams (CBAT)
 - Minor Planet Center (MPC)
 - Recent Comet magnitudes (ICQ/CBAT/MPC)
 - International Comet Quarterly (ICQ)
 - Astronomical Headlines
 - Minor Planet & Comet Ephemeris Service
 - Orbital Elements for Software Packages
 - Observable Comets
International Year of Astronomy 2009 (IAU IYA2009) The Universe: Yours to Discover
 - Galilean Nights What Galileo observed in the sky; The Moon, Jupiter and more (22-24 October '09)
International Dark-Sky Association (IDA)
International Occultation Timing Association (IOTA)
International Society for Archaeoastronomy and Astronomy in Culture (ISAAC)
Internet Amateur Astronomers Catalog (IAAC) (NetAstroCatalog Mailing List, Lew Gramer)
Introduction to Earth Sciences I (Professor John C. Mutter. Department of Earth and Environmental Sciences, International and Public Affairs, Columbia University)
Introduction to Physical Geography (Christine M. Rodrigue Ph.D., California State University, Long Beach)
Institute of Physics (IOP)
IOTA Asteroidal Occultation, Mid-Atlantic Occultation, Eclipse, and Lunar Impactors Page
ITER (Large-scale international scientific experiment to produce commercial energy from tokamak atomic fusion)

Java based Mars geographical information system - JMARS (Arizona State University)
John Baez's Stuff (Quantum Gravity & n-Categories)
JunkScience.com (All the junk that's fit to debunk. Steven Milloy, Publisher)

Kid's Cosmos (Science Resources for Teachers and Students)

Laser Interferometer Gravitational Wave Observatory (LIGO) (California Institute of Technology)
 - Gravitational Waves Detected 100 Years After Einstein's Prediction (February 11, 2016)
Lawrence Berkeley National Laboratory
Lick Observatory (University of California Observatories)
Life32 Conway's Game of Life (Cellular Automata) freeware for MS Windows (Johan Bontes)
Lights in the Dark Photos & News About Our Solar System, by J. Major
Lincoln Near Earth Asteroid Research (LINEAR) (MIT Lincoln Laboratory)
Linda Hall Library of Science, Engineering and Technology - Online Exhibitions
Living Reviews in Relativity (Research Journal, Max Planck Institute)
Lockheed Martin Solar and Astrophysics Laboratory (LMSAL)
Lost Valley Observatory and Astrophotography (Keith Quattrocchi)
Lowell Observatory (Orbital Elements for Asteroids)
 - Asteroid Data Services
Lunar and Planetary Institute Universities Space Research Association (USRA)
 - Digital Lunar Orbiter Photographic Atlas of the Moon
Lunar and Planetary Laboratory (LPL) (University of Arizona, Tucson)
Lunar Occultations and Grazes (IOTA)
Lunar Picture of the Day (LPOD)
Lunar Reconnaissance Orbiter Camera (LROC)
Lunar Research Institute (Dr. Alan Binder)

Malin Space Science Systems (MSSS)
Map Collection (Perry-Castañeda Library, University of Texas, Austin)
Marquette Astronomical Society (Northern Michigan)
Mars Atmosphere and Volatile Evolution Mission (MAVEN) (Nov. 18, 2013)
Mars on Earth - The Haughton-Mars Project (HMP) (A study of an Artic analog for Mars)
Mars Odyssey Mission - Thermal Emission Imaging System (THEMIS)
Math Open Reference (John Page)
MathPages (Kevin Brown)
Mauna Loa Solar Observatory (HAO/NCAR)
McDonald Observatory (University of Texas)
MCell 1D and 2D Cellular Automata (Game of Life) explorer freeware for MS Windows (Mirek Wójtowicz, Poland)
Mel Bartels, BB AstroDesigns (Computer Operated Telescopes and Telescope Making)
 - Collimating a F3 Telescope
MESSENGER Mission (Mercury Surface, Space Environment, Geochemistry and Ranging. Johns Hopkins University)
Messier45.com (Deep Sky Browser, Messier Gallery, Herschel 400)
Meteor Showers Online (Gary Kronk)
Metric Conversions (Metric conversion calculators and charts)
Michelson Doppler Imager project (MDI) (Stanford-Lockheed Solar Oscillations Investigation (SOI) - SOHO. Terminated on 12 April 2011)
Mike Brown (Planetary Astronomy, Caltech)
Milkyweb Astronomical Observatory Guide (Wolfgang Grond)
Molecular Expressions (Images from the Microscope. Secret Worlds: The Universe Within - Powers of 10. Java)
Moonglow Observatory (Fred Bruenjes' Astronomy Stuff)
Mount Graham International Observatory (MGIO) (University of Arizona)
Mount Wilson Observatory
MrEclipse.com The Ultimate Resource For Eclipse Photography (Fred Espenak)
Multiwavelength Astronomy Gallery (Cool Cosmos - Infrared)

NGA: GEOnet Names Server (GNS) (Geographic Names Data: Coordinates)
National Center for Atmospheric Research (NCAR)
National Geographic Society Magazine Online (con versión en Español)
National Radio Astronomy Observatory (NRAO)
  Atacama Large Millimeter Array (ALMA)
  Robert C. Byrd Green Bank Telescope (GBT)
  Very Large Array (VLA)
  Very Long Baseline Array (VLBA)
National Science Foundation (NSF)
National Solar Observatory (NSO)
National Space Science and Technology Center (NSSTC) (University of Alabama in Huntsville)
National Space Society (NSS)
National Optical Astronomy Observatories (NOAO) Cerro Tololo Inter-American Observatory (CTIO) and Kitt Peak National Observatory (KPNO)
Naval Research Laboratory - Large Angle and Spectrometric Coronagraph Experiment (LASCO)
Naval Research Laboratory - Monterey: Marine Meteorology Division (NRL-MRY)
Naval Research Laboratory - Monterey: Satellite Meteorology (NRL-MRY)
NEAR - Shoemaker (Near-Earth Asteroid Rendevouz with Eros)
Neil Hammerschlag (Rosenstiel School of Marine and Atmospheric Science, University of Miami)
New England Meteoritical Services (Meteorites)
Nobelprize.org (Nobel Prizes, Nobel Foundation)
Nongovernmental International Panel on Climate Change (Climate Change Reconsidered)
NOVA (PBS Science Online Programming)
 - Einstein's Big Idea (Relativity)
 - Galileo's Battle for the Heavens (The birth of science)
 - Origins: Series Overview (The Beginning of Everything)
 - The Elegant Universe (String Theory)
 - To the Moon (The science and engineering story)
 - Tracking El Niño
Northeast Florida Astronomical Society (NEFAS)
Northern Virginia Astronomy Club (NOVAC)
Novaspace Galleries (Alan Bean)
NuSTAR (Nuclear Spectroscopic Telescope Array, High energy X-ray orbiting telescope. Launched on June, 13 '12)

OnEarth Magazine (Environmental Issues, NRDC)
On-Line Biology Book (Michael J. Farabee Ph.D. September 2006)
On the Origin of Species by Means of Natural Selection - Charles Darwin (Online Library of Literature)
Orbitron Satellite Tracking System (Sebastian Stoff. Free Satellite tracking software)

PALEOMAP Project (The history of Earth and Climate, Christopher R. Scotese)
Palomar Testbed Interferometer (PTI) (Until 2008 the Palomar Testbed Interferometer (PTI), was operated by the Jet Propulsion Laboratory. It has since been decomissioned)
Paul Goelz's astronomy pages (Astronomy, Videoastronomy, modification to the Supercircuits PC23C video camera)
Peoria Astronomical Society
Phoenix Mars Mission (NASA-LPL, Underground water, 4 August 2007 - 25 May 2010)
PhysicalGeography.net (Dr. Michael Pidwirny, University of British Columbia Okanagan)
Physics (American Physical Society)
 - Physics Central
physicsworld.com (Physics World Magazine)
Phys.Org (Science, research and technology news service)
 - Astronomy News
Planetary Rings Node (SETI Institute, NASA Planetary Data System)
Proceedings of the National Academy of Sciences of the United States of America
Professor Edward L. (Ned) Wright (Vice Chair for Astronomy, WISE Principal Investigator, UCLA)
Project Gutenberg (Fine Literature Digitally Re-Published, Your FREE Personal Library, Free ebooks)
Projects in Scientific Computing (Pittsburgh Supercomputing Center)
Puckett Observatory (Automated Supernova Search. Tim Puckett)

Quantum Mechanics (Prof. dr. K. Michielsen, Prof. dr. H. De Raedt. embd.be)
Quantum Mechanics for Beginners (A fun-filled introduction to Quantum Mechanics and Chaos Theory, by Arie Uittenbogaard)
Quantum Physics I (Prof. Allan Adams lectures; notes and videos. Spring 2013, MIT OpenCourseWare)

Real Time Satellite Tracking And Predictions (n2yo) (ITPROSTAR)
Relativity Tutorial (Ned Wright, Vice Chair for Astronomy, UCLA. 2009)
Revista Latino-Americana de Educación en Astronomía (RELEA) (en Portugués, Castellano e Inglés)
Revista Universo Digital - Liga Iberoamericana de Astronomía (LIADA) (en Castellano)
RichardDawkins.net (Richard Dawkins Foundation and Website)
Robert Reeves - Astrophotography
Robinson Lunar Observatory
Robotic Optical Transient Search Experiment (ROTSE) (Search for astrophysical optical transients, since March 1998)
Rossi X-ray Timing Explorer (RXTE) (Massachusetts Institute of Technology - MIT)

Saguaro Astronomy Club
San Jose Astronomical Association
SandlotScience.com (Science and Optical Illusions)
SciDev Magazine Online (A free access gateway to information about science and technology for developing countries)
Science Magazine Online (American Association for the Advancement of Science - AAAS)
Science Timeline (Marks in the evolution of science)
Science U (Learn About Science)
Scientific American (Science News, Articles and Information)
Seeing Our World in a Different Light (Cool Cosmos - Infrared Light Lessons)
Sentinel Mission (The first comprehensive dynamic map of the inner solar system. B612 Foundation)
 - (B612 Mission: To significantly alter the orbit of an asteroid, in a controlled manner, by landing a nuclear powered plasma engine directly on it, to push the asteroid out of its current orbit, just enough to avoid an impact with Earth)
SETI@home BOINC project. For MS Windows, Macintosh, Linux, Android
  A scientific experiment that harnesses the power of hundreds of thousands of Internet-connected computers in the Search for Extra-Terrestrial Intelligence. You can participate by running a screensaver program that downloads and analyzes radio telescope data. There's a small but captivating possibility that your computer will detect the faint murmur of a civilization beyond Earth. (Windows: 710KB Screen-Saver download, 350KB each Data Unit. 32MB RAM, 8-bit color in 800x600 resolution display requeried)
  Un experimento científico que utiliza el poder de cientos de miles de computadoras con conexión al Internet para la Búsqueda de Inteligencia Extra-Terrestre. Ud. puede participar corriendo un "Screen-Saver" que baja y analiza datos de radio-telescopios. Hay una pequeña, pero cautivadora posibilidad de que su computador detectara el leve murmullo de una civilización extra-terrestre. (Windows: 710KB Screen-Saver download, 350KB cada Unidad de Datos. 32MB RAM, color de 8 bits en un display con resolución de 800x600 requeridos)
SETI Institute (To explore, understand and explain the origin, nature and prevalence of life in the universe)
SETI League (Searching for Extra-Terrestrial Intelligence)
Sharkwater (Film by Rob Stewart. Exploring and saving sharks)
Shark Research Institute (Shark conservation, education, research)
Sierra Remote Observatories (Robotic imaging and data acquisition. California, Sierra Nevada Mountains)
Sistema Regional de Visualización y Monitoreo de Mesoamérica (SERVIR) (Sismos, Volcanes, Tormentas, Incendios)
Sky & Telescope (Astronomy News, Tools & Resources)
Sloan Digital Sky Survey (Mapping the Universe)
Smithsonian Institution (Founded in 1846. The world's largest museum and research complex)
 - Global Volcanism Program (National Museum of Natural History)
 - Smithsonian National Air & Space Museum
Solar Radiation and Climate Experiment (SORCE) (Launched on January 25, 2003)
Solar Terrestrial Activity Report (by Jan Alvestad)
Sondas Espaciales (Misiones a otros mundos y la exploración del Sistema Solar) (en Castellano)
Southeastern Association for Research in Astronomy (SARA) (Kitt Peak in Arizona, Cerro Tololo in Chile)
South Florida Amateur Astronomers Association (SFAAA) (The Fox Observatory. Sunrise, FL)
South Pole Telescope (SPT) (Dark Energy, Cosmic Microwave Background. University of Chicago)
Southern Cross Astronomical Society (SCAS) (Winter Star Party. West Summerland Key, Florida)
Space.edu (University of North Dakota - Department of Space Studies)
Space.com (Space and NASA News - Universe and Deep Space Information)
Space Archive (Space and Astronomy Information. Ventura County, California. Brian Webb)
Spaceflight Now (Online Space News)
Space Exploration Technologies Corporation - SpaceX (Commercial Orbital Transportation Services, Dragon Spacecraft)
Space Explorers, Inc. (Bringing Space Into the Classroom)
Space Frontier Foundation (Large-scale permanent settlement of space)
Space News
SpaceRef.com (Space Exploration News)
Space Time Travel (Relativity Visualized)
Spacetime Wrinkles (One of the best Relativity sites in the Web,
part of NCSA's Multimedia Online Expo, Science for the Millennium,
a "pavilion" of the Internet 1996 World Exposition)
Staigerland Solar Eclipse Webcasts (Philip Staiger)
Stanford Linear Accelerator Center (SLAC) (Stanford University, U.S. Dept. of Energy)
Stanford SOLAR Center (Stanford University)
StarDate Online - Your Guide to the Universe (McDonald Observatory, University of Texas)
StarGarden Foundation to promote public interest and knowledge of astronomy (Victor & Jennifer Winter)
Star Gazer (Jack Horkheimer, 1938-2010) One year of weekly naked-eye astronomy shows
Starlight Foundation (Starlight Initiative for the night sky. La Laguna, Tenerife. Since 2007)
Stephen Wolfram Scientist, Creator of Mathematica, and Author of A New Kind of Science (NKS Online)
 - Wolfram|Alpha (Computational Knowledge Engine, launched May 18, 2009)
 - Wolfram Research (Mathematica: a numeric and symbolic computational engine, graphics system,
     programming language, documentation system, and advanced connectivity to other applications)
 - Wolfram Science (The Official Website of Stephen Wolfram's A New Kind of Science)
 - Eric Weisstein's Science World (Worlds of Astronomy, Biography, Chemistry, Mathematics, Physics)
 - Wolfram Educational Portal (Resources for pre-college grade levels)
 - Wolfram Public Resources, including Integral Calculator: Wolfram Mathematica Online Integrator,
    Demonstrations - Interactive visualizations in math and science - powered by Wolfram Mathematica Player
Stratospheric Observatory for Infrared Astronomy (SOFIA) (NASA & German Aerospace Center - DLR)
Submillimeter Wave Astronomy Satellite (SWAS) (Chemical composition of interstellar gas clouds, from Dec. 05, 1998)
Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) (U.S. Naval Research Laboratory - NRL)
Sungazer (Observing the Sun in Hydrogen-Alpha and Calcium Light)
Sungrazing Comets (SOHO Comets) (U.S. Naval Research Laboratory - NRL)

Tanner's General Chemistry (Tanner and Weston McCarron)
TerraServer-USA (Maps and aerial photographs of the United States)
The Astrolabe (The Electric Astrolabe. by James E. Morrison, Janus)
The Ayn Rand Institute (Promoting reason, rational self-interest, individual rights and laissez-faire capitalism)
 - Ayn Rand's Ideas (A Philosophy for Living on Earth)
The Constellations and their Stars (Chris Dolan)
The Constellations Web Page (Richard Dibon-Smith)
The Electronic Universe (University of Oregon, Department of Physics)
The First Men on the Moon: The Apollo 11 Lunar Landing (Experience the Lunar Landing - An online interactive)
The Hayden Planetarium (American Museum of Natural History)
The Mythology of the Constellations (Cathy Bell)
The New York Times: Science
The Official String Theory Web Site (Dr. Patricia Schwarz)
The Particle Adventure (en 8 idiomas, incluyendo La Aventura de las Partículas, en Castellano)
The Planetary Society (Where did we come from?, Are we alone?)
The Second Law of Thermodynamics (Frank L. Lambert, Professor Emeritus, Occidental College, Los Angeles)
The Shallow Sky (Observing the Solar System, by Akkana Peck)
The Talk.Origins Archive (Exploring the Creation/Evolution Controversy)
The Telescope Review Web Site (Ed Ting)
The Telson Spur (The Snark Hunter's Page, Links in The Study of Time and Evolution)
The Tree of Life Web Project (Information about phylogeny and biodiversity)
The University of California Planet Search Project (exoplanets.org)
The University of North Dakota - Sun-Earth-Moon System (SEMS) Project & Webcasts
The Van Allen Probes (Earth's Radiation Belts. Johns Hopkins University, Applied Physics Laboratory. From Aug. 30, '12)
The WWW Virtual Library (The oldest Web catalog, started by Tim Berners-Lee, creator of HTML and the Web)
Timeline Index (Chronologies of People, Periods, Places, Events)
Transistorized! (The History of the Invention of the Transistor. Ira Flatow, PBS)
Transition Region and Coronal Explorer (TRACE) (The magnetic field in the Solar atmosphere. Since June 21, 2010)
Tropical Rain Forest Information Center (TRFIC) (The current state of the world's tropical forests)
Two-Micron All-Sky Survey (2MASS) at IPAC (University of Massachusetts, Amherst. Spring 1997 to Spring 2001)

UCLA - Division of Astronomy & Astrophysics
UCSB Experimental Cosmology Group (Experimental Astrophysics)
United Space Alliance (Space Shuttle main contractor, with live mission tracking & telemetry data, NASA-TV links)
Unisys Weather (A complete source of graphical weather information)
Universe Today (Space News from around the Internet, updated every weekday)
University of Alabama - Department of Physics and Astronomy (Astronomical Images)
University of Arizona - Department of Astronomy and Steward Observatory
University of California Museum of Paleontology (UCMP) (Phylogeny, Geology & Evolution Exhibts)
University of California Observatories (Lick Observatory)
Universo Online - Su Guía para el Universo (Observatorio McDonald de la Universidad de Texas, en Castellano)
Usenet Physics and Relativity FAQ (General, Particle and Nuclear, Quantum Physics, Relativity and Cosmology)
US Geological Survey Home Page (USGS)
 - Astrogeology: Gazetteer of Planetary Nomenclature (USGS-IAU-NASA)
 - Astrogeology: Map-a-Planet (PDS) (Mercury, Venus, Moon, Mars, Moons of Jupiter, Moons of Saturn)
 - Earth Explorer
 - Earthquake Hazards Program
 - Geomagnetism Program
 - La Ciencia del Agua para Escuelas
 - Landsat Project
 - Water Science School
U.S. Global Change Research Information Office
U.S. National Virtual Observatory (NVO)
U.S. Naval Observatory (USNO) (Naval Oceanography Portal)
 - Astronomical Applications Department (Data Services)
USNO Flagstaff Station Integrated Image and Catalogue Archive Service
US Virtual Astronomical Observatory

Vatican Observatory (Castel Gandolfo, Italy)
 - Vatican Advanced Technology Telescope - VATT (Mount Graham International Observatory. Safford, Arizona)
   (1.8 m f/1.0 honeycombed construction borosilicate primary mirror, 0.38 m f/0.9 Zerodur concave secondary mirror)
Ventanas al Universo (Ciencias de la Tierra y el Espacio)
Views of The Solar System (Calvin J. Hamilton) English
 - Vistas del Sistema Solar (Calvin J. Hamilton) Castellano
 - Vistas do Sistema Solar (Calvin J. Hamilton) Português
 - Regards sur le Système Solaire (Calvin J. Hamilton) Fraçais
 - Ansichten des Sonnensystems (Calvin J. Hamilton) German
Violence in the Cosmos (Explosive Processes and the Evolution of the Universe. Michael W. Guidry)
Visual Quantum Mechanics Tutorials (Kansas State University - Physics Education Group)
Visual Satellite Observer's Home Page (SATOBS)
 - MIR Space Station - 15 Years In Orbit End (19 February 1986 - 26 March 2001)
Voyager Plasma Wave Investigation (Voyager 1 & 2: 1977-2020? The University of Iowa)

Warren Astronomical Society (Since 1961. Stargate Observatory. Warren, Michigan)
Weasner's Mighty ETX Site (Meade ETX telescopes information. September 1996 - August 2013. Michael L. Weasner)
Weasner's LXD55 Site (Meade LDX telescopes information. November 2002 - May 2008. Michael L. Weasner)
Weatherbase (World monthly weather records and averages)
Weather Underground (Weather Forecast & Reports - Long Range & Local)
Web Elements.com (An Interactive Periodic Table of the Elements)
We Choose the Moon (The Apollo 11 adventure - John F. Kennedy Presidential Library & Museum)
Wendy Carlos Eclipse Page (Photographs of Total Solar Eclipses since 1963)
Werner Heisenberg (1901-1976) (American Institute of Physics History Center exhibit)
West Texas Astronomers (Midland, Texas)
Whispers from the Cosmos (One of the best Radioastronomy sites in the Web,
part of NCSA's Multimedia Online Expo, Science for the Millennium,
a "pavilion" of the Internet 1996 World Exposition)
Wide-Field Infrared Survey Explorer (WISE) (launched December '09)
Windows to the Universe (Earth and Space sciences)
William M. Briggs, Statistician (Adjunct Professor of Statistical Science, Cornell University, Ithaca, New York)
WIYN 3.5 m Observatory (Kitt Peak, Arizona)
W. M. Keck Observatory (Twin 10 m telescopes. Mauna Kea, Hawaii)
World Climate (Weather, Rainfall and Temperature Data)
World History: HyperHistory Online (3,000 years of world history)
WorldWide Telescope (Virtual telescope, a Microsoft Web 2.0 visualization software)
World Year of Physics 2005 (Celebrating the 100th anniversary of Albert Einstein's "miraculous year")
WW2010 - the weather world 2010 project (University of Illinois)
 - Meteorology online guides (Light and Optics, Clouds and Precipitation, Forces and Winds, Air Masses and Fronts, Weather Forecasting, Severe Storms, Hurricanes, El Niño, The Hydrologic Cycle)

Yakima Astronomical Society (YAS) (Washington State)
Yohkoh Public Outreach Project (Images and movies of the Sun. X-ray telescope satellite. Aug. 31, '91 - Dec. 14, '01)

Zooniverse (Citizen Real Science Online projects)

Countries (Países):

Argentina:
Asociación Entrerriana de Astronomía (AEA) (Desde el 24 de Septiembre de 1986)
Cielo Sur (Astronomía desde el Hemisferio Sur)
espacial.com (Foros del espacio y astronomía)
Espacio Profundo (Difución de la astronomía y sus ciencias conexas)
Instituto Argentino de Radioastronomía (IAR) (Desde Marzo de 1966)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Met.net (Clima y Meteorología)
Observatorio Astronómico de Córdoba (OAC) (Universidad Nacional De Córdoba. Fundado el 24 de Octubre de 1871)
Planetario Carl Sagan (Planetario Móvil)
Sur Astronómico

Australia:
Australian Astronomical Observatory (AAO) (Inaugurated on 16 October 1974)
Astronomical Society of South Australia (Founded in 1892)
Cosmodome (MirrorDome Mobile/Fixed Planetarium Projection System)
Einstein Light (Relativity: Einstein's theory in animations and film clips. University of New South Wales)
Gordon Garradd's Astronomy Page
Grove Creek Observatory (GCO) (Established in 1985. Jim Lynch: Director and Founder)
High Resolution Lunar and Planetary Imaging (Zac Pujic)
Mount Stromlo & Siding Spring Observatories (Australian National University)
The Mars Society - Australia

Belgium:
International Meteor Organization (IMO) (Founded in 1988)
La Terre, le grand aimant - De Magnete, W. Gilbert (David P. Stern. Française, Joseph Lemaire)
Solar Influences Data Analysis Center (SIDC) (Royal Observatory of Belgium)

Brasil:
Laboratório Nacional de Astrofísica (MCT) (13 de Março de 1985)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Revista Latino-Americana de Educación en Astronomía (RELEA) (Lanzada en 2004. En Portugués, Castellano e Inglés)
SciELO.org (Scientific Electronic Library Online)
Southern Astrophysical Research (SOAR) Telescope (4.1 meter aperture)

Canada:
Astronomy and Astrophysics at the University of British Columbia
Auriga Imaging (RegiStar, Automatic image registration for astrophotography. MS Windows)
Canadian Galactic Plane Survey (CGPS) (To map the interstellar matter in a large swath of our own Milky Way Galaxy)
Canadian Hurricane Centre (CHC)
Canadian Institute for Theoretical Astrophysics (CITA)
Canadian Space Agency (CSA) (Founded: March 1, 1989)
Edmonton Centre of The Royal Astronomical Society of Canada (Since 1932)
Magnetic Declination Calculator (Natural Resources Canada)
Les Neuf Planètes (Bill Arnett)
Liquid Mirror Telescopes (The University of British Columbia, Department of Physics and Astronomy)
Mike Boschat's Astronomy Page (Halifax, Nova Scotia)
Microvariability & Oscillations of STars (MOST) (Canada's First Space Telescope)
Space Weather Canada / Météo Spatiale Canada (Natural Resources Canada)
The Royal Astronomical Society of Canada (La Société Royale d'Astronomie du Canada. Founded in 1868)

Chile:
Círculo Astronómico (Educar con Astronomía. Desde 1999)
European Southern Observatory (ESO) (Paranal Very Large Telescope Interferometer (VLTI). La Silla Observatory. Atacama Large Millimeter Array (ALMA). Since 5 October 1962)
 - New Technology Telescope (NTT) (La Silla, 3.58 metre)
 - Very Large Telescope (VLT) (Four 8.2 m diameter Telescopes)
 - European Extremely Large Telescope (E-ELT) (Project for a 40 m-class telescope at Cerro Armazones)
Gemini Observatory (Twin 8.1-meter diameter optical/infrared telescopes at Mauna Kea, Hawaii & Cerro Pachón, Chile)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Observatorio Astronómico Melaga (OAM) (Eduardo Leyton. Santiago de Chile)
Turismo Astronómico en Chile

China:
Science in China (Scientists, Astronomy, Medicine, Archeology, Mathematics)

Colombia:
Astronomía Autodidacta (Boyacá. Carlos Andrés Carvajal Tascón)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Observatorio Astronómico Universidad Sergio Arboleda (Bogotá)

Costa Rica:
Asociación Costarricense de Astronomía (ACODEA) (Fundada en 1987)
Fundación CIENTEC (Creada en 1988. San José)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)

Cuba:
Astronomía Amateur Cubana (La Habana 2003, por Carlos Alberto Heredero Gracia)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Observatorio Astronómico - Universidad de La Habana (Fundado en 1914)
ProAstronomía (Desde Octubre 16, 2001)

Denmark:
DTU Space - National Space Institute (NSI) (Established in 2007. Technical University of Denmark)
Tycho Brahe Planetarium (Copenhagen)

Ecuador:
Agencia Espacial Civil Ecuatoriana (EXA) (Satélite NEE-01 Pegaso, Abril 26 '13. Satélite NEE-02 KRYSAOR Pegaso, 21 Noviembre de 2013)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)

El Salvador:
Asociación Salvadoreña de Astronomía (ASTRO) (Desde el 17 de enero de 1991)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)

España:
Agencia Estatal de Meteorología (AEMET) (Desde el 8 de Febrero de 2008)
Agrupación Astronómica de Gran Canaria (AAGC) (Fundada el 1 de Junio de 1990)
Agrupación Astronómica de Tenerife (A.A.T.) (Fundada el 20 de Mayo de 1987)
Astroguia.org (Astronomia y Ciencias relacionadas. Desde el 26 de Octubre de 2005)
Astronomía Digital (info.astro) (Revista internacional de astronomía en Español. Las Palmas de Gran Canaria. Víctor R. Ruíz. Desde Septiembre 1998)
Astronomía en Internet (Cómo usar el Internet para aprender a observar el cielo y a elegir un telescopio. Por Jorge A. Vázquez Parra)
AstroRED (Desde Diciembre 1995. Alex Dantart)
Astroseti.org (Desde el 18 de Octubre de 2004)
Consejo Superior de Investigaciones Científicas (CSIC) (Creado en Noviembre 24, 1939)
Departamento de Astrofísica - Universidad Complutense de Madrid (UCM)
educa-ciencia.com (Ciencia y Astronomía para la educación. Jorge Antonio Vázquez Parra. Se fundó en Agosto de 2007)
El Ojo en el Cielo (Blog sobre Estrellas Variables. Francisco Rodríguez Bergali. Desde el 12 de Septiembre de 2007)
Elsegundoluz.com (Un proyecto de comunicación de la Ciencia. Desde Enero 12, 2008)
El Universo y el hombre (Por Jaime Escobar Morales)
Estudio y Reconstrucción de la Gnomónica Hispanomusulmana (Germán Moreno de la Cruz. Desde Marzo 28, 2004)
Gran Telescopio Canarias (GTC) (Telescopio de 10.4 m. Observatorio del Roque de los Muchachos, La Palma. Desde el 13 de Julio de 2007)
Infoastro (Víctor R. Ruíz, desde Agosto 6, 1997)
Instituto de Astrofísica de Canarias (Observatorio del Roque de los Muchachos, Palma. Observatorio del Teide, Tenerife)
Instituto Nacional de Técnica Aeroespacial (INTA) (Creado en 1942)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Los Nueve Planetas (en AstroRED. Original de Bill Arnett y Arnaud Riess)
El tiempo (Meteored. Información, previsión, y predicción meteorológica)
Noticias de la Ciencia y la Tecnología (NCYT) / Noticias del Espacio (Amazings.com. Manuel Montes y Jorge M. Colome. Desde 1997)
Observatori Astronòmic de Mallorca (Illes Balears. Desde 1991)
Observatorio Astronómico Municipal Monte Deva - Gijón (José Ramón Vidal)
Planetario de Pamplona (Navarra. Desde 1993)
Red de Investigación sobre Bólidos y Meteoritos (SPMN)
Sociedad Astronómica Asturiana Omega (Desde 1981)
Sociedad Astronómica de España y América (SADEYA) (Fundada en 1911)
Sociedad de Observadores de Meteoros y Cometas de España (SOMYCE) (Desde 1988)
Starlight Foundation (Starlight Initiative for the night sky. La Laguna, Tenerife. Since 2007)
TuTiempo.net (Información meteorológica de todo el mundo)
Vistas del Sistema Solar (Calvin J. Hamilton. Traducido al Español por: Mario L. Saucedo y Antonio Bello)

Finland:
Finnish Amateur Astronomy Home Page (Veikko Mäkelä, Mika Pirttivaara)
Polar Image Atmospheric Phenomena (Pekka Parviainen. Since 1973)

France:
Astrophotography - Thierry Legault (High Resolution CCD Imaging, Française/English)
 - The collimation (Collimation is the adustment of the alignement of each optical element of a telescope with regard to the others)
C2A Planetarium Software (MS Windows Freeware. Author: Philippe Deverchère)
Cartes du Ciel - Skychart (Free Astronomy software, Celestial atlas. Patrick Chevalley. Linux, MS Windows, OS X. Con versión en Castellano)
Centre de Données astronomiques de Strasbourg (CDS) (Strasbourg astronomical Data Center)
 - Simbad Astronomical Database
 - VizieR Astronomical Catalog Service
 - The Aladin Interactive Sky Image Atlas
Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) (Founded on June 25, 1795. Française/English)
Regards sur le Système Solaire (Calvin J. Hamilton)
Shadows Design sundials and astrolabes (Française/English) François Blateyron. Freeware (MS Windows)
Astrium GeoInformation Services: Satellite maps & images - geospatial solutions (SPOT Satellites)
Virtual Moon Atlas Free software for Moon observation or survey (Patrick Chevalley, Christian Legrand. English version, con versión en Castellano)
WinStars (Shareware planetarium software - MS Windows. Franck Richard)

Germany:
Ansichten des Sonnensystems (Calvin J. Hamilton)
Astrophotography with small telescopes (Stefan Beck)
Astronomiae Historia / History of Astronomy (Wolfgang R. Dick. Created: 16 Jan. 1995)
Axel Mellinger's Astrophotography Page (Photograph of the whole Milky Way and Virtual Reality Milky Way Panorama)
Das Planetarium 1900 - 2100 (Astroexcel Astronomie Planetarium. Thomas Kraus. Freeware. MS Windows)
Einstein Online (Explaining Einstein's theories of relativity to a general audience. English version, Max Planck Institute)
German Aerospace Center (DLR) (English version)
 - ROentgen SATellite (ROSAT) Mission (All-sky survey of X-ray sources, 1 June 1990 - 12 February 1999)
Heavens-Above (Sky and Satellite Visibility. Developed and maintained by Chris Peat)
International Occultation Timing Association - European Section (IOTA-ES) (Hannover)
Max Planck Society (Establishment in 1948. English version)
Physics and Astronomy (Java Applets for detailed Solar and Lunar data. Jürgen Giesen)
The Munich Astro Archive (MAA) (Christine Kronberg. Since October 1997)

India:
Indian Space Research Organisation (ISRO) (Formed on August 15, 1969)
 - Chandrayaan-1 (Satellite in Lunar polar orbit for high-resolution remote sensing of the Moon in visible, near infrared, low energy X-rays and high-energy X-ray regions. Lauched on October 22, 2008, achieved operational 100 km circular Lunar polar orbit on November 12, 2008. The Moon Impact Probe was ejected and hard landed on the Lunar surface near the South Polar Region after a 25 minutes journey, on November 14, 2008)
 - Mars Orbiter Mission (Satellite in elliptical orbit around Mars, for observation of physical features and a limited study of the Martian atmosphere. Launch Date: November 5, 2013. The spacecraft would be inserted into the Martian Orbit on September 24, 2014)
India-WRIS (Web-enabled Water Resources Information System. Since December 10, 2009. WebGIS since December 7, 2010)

Ireland:
Astronomy Ireland (National Astronomy Club of Ireland. David Moore. Dublin. Founded in 1990)

Italia:
Agenzia Spaziale Italiana (ASI) (Founded in 1988)
Asteroid Information Services: (Space Mechanics Group, Department of Mathematics, University of Pisa)
 - Asteroids Dynamic Site (AstDyS)
 - Near Earth Objects Dynamic Site (NEODyS)
Astrofili.org: (Portale per l'astronomia in Italia, Fabio De Sicot)
 - Gruppo Astrofili Cinisello Balsamo (GACB) (Fondato nel Settembre 1983)
 - Gruppo Astrofili Persicetani (Gapers) (Planetario, Osservatorio Giorgio Abetti e Museo del Cielo e della Terra)
 - GruppoSole Ricerche Solari Italia (GsRSI) (Fondato nel 1999)
 - Osservare il Cielo
 - Ricerca Supernovae Extragalattiche (Gruppo Omega. Palermo. Nato nel 1975)
Astrophotography (Lorenzo Lovato)
Bellatrix Astronomical Observatory (Ceccano. Gianluca Masi. Fondato nel 1997)
Cielo e Terra ["Sky Draw - Mappa del Cielo", "Earth Map - Mappa della Terra", "Eclipses & Earth - Eclisse e Terra", "Planetarium - Planetario"] (Piero Massimino. Osservatorio Astrofisico di Catania - CAO)
Circolo Astrofili Talmassons (Lucio Furlanetto. Fondato nel 1997)
Dagli astronomi alle astronavi (David P. Stern. Aggiornato al 17 Agosto 2009)
International Supernovae Network (Stefano Pesci)
inquinamentoluminoso.it (by Pierantonio Cinzano)
Istituto di Radioastronomia (IRA), Bologna (INAF. Created in 1970)
Istituto Nazionale di Fisica Nucleare (INFN) (Founded on August 8, 1951)
Osservatorio Astrofisico di Catania (CAO)
Museo Galileo - Florence
Nico Lonetti - ASTRONOMIA
The Abdus Salam International Centre for Theoretical Physics (ICTP) (Founded in 1964)
The Nine Planets - Versione italiana (Bill Arnett)

Japan:
Astro Arts (Tokyo. Established in July 28, 1981)
Astronomy in Japan Page (Steven Renshaw. Since December 1995)
Data ARchives and Transmission System (DARTS)
Hinode Science Center at NAOJ (National Astronomical Observatory of Japan (NAOJ). The Hinode (Solar-B) is a highly sophisticated observational satellite equipped with three advanced solar telescopes. Its solar optical telescope (SOT) has an unprecedented 0.2 arcsec resolution for the observation of solar magnetic fields. The X-ray telescope (XRT) has a resolution of three times as high as Yohkoh, and the EUV imaging spectrometer (EIS) has sensitivity ten times as high as the ESA SOHO instrument. It was launched on 22 September 2006 UT (23 September in Japan time))
Ikufumi Makino - Comets
Institute of Space and Astronautical Science (ISAS) (Founded on 1955)
 - Asteroid Exploration HAYABUSA (MUSES-C) (Mission lauched on May 9, 2003. In November 2005 it successfully landed on asteroid 25143 Itokawa. Samples from the asteroid were brought to Earth in June 2010.)
 - Solar Observation HINODE (SOLAR-B) (Investigation of magnetic activity of the Sun including its generation, energy transfer and release of the magnetic energy. Launched on September 23, 2006)
Japan Aerospace Exploration Agency (JAXA) (Founded on October 1, 2003)
 - Solar Physics Satellite "HINODE" (SOLAR-B) (An observatory satellite to study the impact of the Sun on the Earth. The HINODE (SOLAR-B), is the successor to the orbiting Solar observatory YOHKOH (SOLAR-A). The satellite was coordinated and developed by the United Kingdom, the United States and Japan. HINODE will carry a coordinated set of optical, X-ray, and EUV instruments that perform highly accurate measurements of magnetic fields, electrical currents and velocity fields in the solar atmosphere and corona. Launched on September 23, 2006)
 - Asteroid Exploration HAYABUSA2 (Mission lauched on December 3, 2014 (at 13:22:04 on December 3, 2014 (JST), 04:22:04 UTC). It will land on asteroid 1999 JU3 in 2018, staying around there for one and half years before leaving the asteroid at the end of 2019 and returning to Earth around the end of 2020)
Seiichi Yoshida's Home Page (Comets and the MISAO Project. Since December 4, 1995)

Jordan:
Jordanian Astronomical Society (Amman. Founded in 1987)

Latvia:
Institute of Astronomy University of Latvia (Riga)

Malta:
The Astronomical Society of Malta (L-Ghaqda Maltija tal-Astronomija. Formed in 1984)

México:
Area de Astronomía en la Universidad de Sonora (Creada el 15 de Febrero de 1990)
Astronomos.org (Autores: Lonnie Pacheco, Carlos Raúl López)
Club de Astronomía Mexitli
Kosmos Scientific (Director: José E. García Batarse. Monterrey. Inicia operaciones en 1989)
 - El Cielo Nocturno
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
MegaCosmos (Jesús Gerardo Rodríguez Flores. Blog. Desde Julio 15, 2004)
Sociedad Astronómica de Aguascalientes (SAA) (Fundada el 29 de Junio de 1991 por el Ing. Luís Gerardo Castillo Macías)
Sociedad Astronómica del Planetario Alfa (SAPA) (San Pedro Garza García, Nuevo León)

Netherlands:
Clear Skies Observing Guides (CSOG) (Guides & Tours of the sky, Victor van Wulfen)
Dutch Open Telescope (DOT) (Observatorio del Roque de los Muchachos, La Palma, Spain. First light on October 1997)
Hallo northern sky (HNSKY) Planetarium program with 10607 deepsky objects and all stars to magnitude 12, and with the original GSC CD-ROM's, GSC-ACT or the USNO to magnitude 15 or more. Displays all planets, the Moon, Sun, moons of Saturn and Jupiter, Mars, Uranus and Neptune and a few hunderd asteroids and comets. By Han Kleijn. Freeware (MS Windows)
Netherlands Institute for Radio Astronomy (ASTRON) (Westerbork and LOFAR Synthesis Radio Telescopes. Founded in 1949)
The Maya Astronomy Page (Michiel Berger. Established in 1996)
The Virtual Tour of the Sun (Michiel Berger)

Norway:
Astronomy.no
Institute of Theoretical Astrophysics, Oslo (Founded in 1934)
time and date.com (by Steffen Thorsen. Stavanger, Norway. Registered in 1997)
UNEP-GRID-Arendal (Environmental Knowledge for Change. Established in 1989)

Paraguay:
Centro Paraguayo de Informaciones Astronómicas (CPIA) (Webmaster: Jorge Maidana)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)

Perú:
La Astronomía en el Perú (Institución virtual)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Planetarium Cusco (Cielos del Sur - Observatorio de astronomía en Cusco)

Portugal:
CCD astrophotography by Pedro Ré (Since October 03, 2005)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Os Nove Planetas (Bill Arnett)

República Dominicana:
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Sociedad Astronómica Dominicana (S.A.D.) (Astrodom. Santo Domingo)

Romania:
The Night Sky This Month (Information about the night sky and articles on astronomical topics. Emil Neata)

Russia:
Russian Space Science Internet Web Server (RSSI) (Established in April, 1993)
Space Research Institute (IKI) (Russian Academy of Sciences. Moscow)
StarCalc (Astronomy planetarium & star mapping program by Alexander Zavalishin. Freeware. MS Windows)

Scotland:
The MacTutor History of Mathematics (Mathematicians, History, Curves. John J. O'Connor, Edmund F. Robertson. University of St. Andrews, School of Mathematics and Statistics)

South Africa:
Cederberg Astronomical Observatory (CAO) (Peter Mack. 240 km north of Cape Town. Since 1984)
South African Astronomical Observatory (SAAO) (Observatory, Cape Town. Established on October 20, 1820)
 - Southern African Large Telescope (SALT) (11 metres hexagonal primary mirror array of 91 individual 1.2 m hexagonal mirrors. Since September 2011)
Willie Koorts's Astronomy Telescope Making and Satellite Tracking Pages

Sweden:
Institute for Solar Physics
 - Swedish 1-m Solar Telescope (SST) (El Roque de los Muchachos, La Palma, Spain. First light on March 2, 2002)

Switzerland:
CalSKY - The Calculated Sky (On-line Configurable Astronomical and Space Calendar. Founded in 1991 by Arnold Barmettler)
European Organization for Nuclear Research (CERN) (European Laboratory for Particle Physics. The CERN laboratory is on the Franco-Swiss border near Geneva. Founded in September 29, 1954)
 - The birth of the World Wide Web:
   - Tim Berners-Lee, a British scientist at CERN, invented the World Wide Web (WWW) in 1989.
   - http://info.cern.ch, the world's first website and server, went live at CERN with The World Wide Web project on December 29, 1990.
   - CERN put the World Wide Web software in the public domain on April 30, 1993.
 - The Large Hadron Collider (LHC) (A 27-kilometre ring of thousands of superconducting magnets at -271.3°C where two high-energy particle beams travel in two beam pipes kept at ultrahigh vacuum, in opposite directions at close to the speed of light before they are made to collide. First started up on September 10, 2008)
Fourmilab - Index Librorum Liberorum (John Walker. Founder of Autodesk, Inc. and co-author of AutoCAD)
 - Home Planet (Comprehensive astronomy / space / satellite-tracking package for Microsoft Windows. September 16, 2006)
The Particle Detector BriefBook (Rudolf K. Bock, at CERN, Geneva, and A. Vasilescu, at IFA, Bucuresti. March 1999)

Ukraine:
Astrometria Project (Measuring the temporary shape and diameter variations of the Sun and Total Solar Irradiance, as well as the fine structure and dynamics of the granulation. On the Russian segment of the International Space Station. 200 mm Solar Limbograph telescope SL-200. Habibullo I. Abdussamatov, Head of the Space Research Laboratory of the Russian Academies of Sciences. Pulkovo Observatory)
National Academy of Sciences of Ukraine - Main Astronomical Observatory (Kyiv. Founded on July 17, 1944)
Taras Shevchenko National University of Kyiv (KNU) (Kiev. Founded in 1834)
 - Celestial calendar
 - Computer Ephemeris
Virtual Roentgen and Gamma Observatory (VIRGO.UA) (Established in 2005)

United Kingdom:
Armagh Observatory (40 miles SW of Belfast, Ireland. Since 1790)
Astronomy Now (Stargazing magazine. Since 1989)
 - Spaceflight Now (Online Space News)
Atmospheric Optics (Light playing on water drops, dust or ice crystals in the atmosphere. Les Cowley)
 - TiltingSun Software (TiltingSun2 is freeware which shows the Sun's orientation, poles, equator, rotation direction, prominence position angles and drift direction for any date, time and location) (for MS Windows)
British Astronomical Association (Formed in 1890)
Cambridge Physics (Cavendish Laboratory, University of Cambridge. Opened in 1874. Educational Outreach)
Cambridge University Astronomical Society (Founded in 1942)
Cardiff University School of Physics and Astronomy (Founded on 24th October 1883)
Cambridge Conference Network (CCNet) (A scholarly electronic network moderated by Benny J. Peiser at Liverpool John Moores University. Geological and historical NEO-catastrophism. Near-Eearth-Objects research. 1997-2003)
chemguide (Helping you to understand Chemistry. By Jim Clark. Since 2009)
Faulkes Telescopes Project (2 free access Robotic Telescopes in Hawaii and Australia. University of South Wales)
Foundations to Chemistry (Adapted from Chemistry, Matter and the Universe by Richard E. Dickerson and Irving Geis. University of Oxford)
h2g2 - The Guide to Life, The Universe and Everything (The Hitchhiker's Guide to the Galaxy. A Douglas Adams creation from 1999)
Institute of Astronomy (IoA) (University of Cambridge. Since 1972)
Jodrell Bank Centre for Astrophysics (Radio Astronomy. University of Manchester. Since 1945)
Poor Meadow Dyke Observatory (PMDO) (Telescope and CCD Webcam Modifications for Astrophotography. Steve Chambers, Norwich, UK)
Royal Observatory Greenwich (RGO) (Astronomy - Time and Longitude. Since 1960 part of the National Maritime Museum. Closure of the RGO at Cambridge in October 1998. Founded in 1675)
ScopeTest.com (Telescope and accessory testing, by Ade Ashford. Since 1994)
Stephen Hawking (Black Holes. Former Lucasian Professor of Mathematics at the University of Cambridge. Director of Research at the Centre for Theoretical Cosmology. Author of A Brief History of Time. Born in London on January 8, 1942)
Sundials in the Internet (Con versión en Español. Since 1997)
The Astronomer Magazine (Observations of astronomical interest. Since 1964)
The Naked Scientists (Science down to its bare essentials. Scientists from Cambridge University)
The Museum of the History of Science (Old Ashmolean on Broad Street, Oxford. Since 1683)
 - The Noble Dane: Images of Tycho Brahe (Danish astronomer. 1546-1601)
The Royal Society (The National Academy of Science in the UK. Since July 15, 1662)
 - Trailblazing (An interactive timeline of science. 1665 to 2010)
The Sky at Nigth (By Sir Patrick Moore (1923-2012), BBC Online. From 1960)
The Society for Popular Astronomy (SPA)
UCL Astrophysics Group (University College London. Since 1999)
Zarya (Maintained by Bob Christy. Soviet, Russian & International Spaceflight)

United Nations:
International Tsunami Information Center
United Nations Coordination of Outer Space Activities (Vienna, Austria)
United Nations Office for Outer Space Affairs (UNOOSA) (Vienna, Austria. Created in December 13, 1958)
Universe Awarness for Young Children (UNAWE) (At Leiden Observatory, Netherlands. Founded in 2006)

Uruguay:
Asociación de Aficionados a la Astronomía - Uruguay (AAA) (Fundada en Octubre 16, 1952. Montevideo)
Kappa Crucis, Telescopios, Planetarios (Planetario Móvil, Astrotienda)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)

Venezuela:
Caracas Astronómica (Astrofotografía. Marcelo Saavedra)
Centro de Investigaciones de Astronomía (CIDA) (Observatorio Nacional Llano del Hato, Edo. Mérida. Desde 1971)
Centro virtual de Meteorología (CvM) (Información meteorológica no oficial y modelos numéricos. Raúl Padrón y Estatio Gutierrez. Desde Febrero, 2008)
 - Astronomía de Venezuela (Información Astronómica para Venezuela)
Desde el patio de mi casa (Astrofotografía. Rafael Pire. Barquisimeto, Edo. Lara)
El tiempo meteorológico en Venezuela (Esteban Perdomo Sánchez. Licenciado en Geografía (UCV). Especialista en meteorología y climatología. Blog. Desde Marzo, 2011)
Instituto Nacional de Meteorología e Hidrología (INAMEH) (Desde 2008)
Greg Drayer Andrade, Ph.D. (Ingeniero electricista y magíster en ingeniería de sistemas)
Liga Iberoamericana de Astronomía (LIADA) (Creada el 12 de Diciembre de 1982 en Montevideo, Uruguay)
Meteorología en Venezuela (Luis Mujica)
Observatorio ARVAL (Información astronómica. Andrés Valencia y Arnaldo Arnal. Desde Febrero, 1996)
Observatorio Rofh (Ing. Franz Hernández. Creado en 1998)
Servicio de Hidrografía y Navegación de Venezuela (SHN)
Servicio de Meteorología de la Aviación (Creado en Octubre 10, 1947)
Sociedad Mundial del Futuro Venezuela (SMF Venezuela) (Constituída en Caracas en el año 2001)
Tayabeixo: Asociación Larense de Astronomía, ALDA (Desde 1985)



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