... Mercury: Closest Planet to the Sun . ... The Sun Erupts . ... Space Shuttle Atlantis lands at Edwards Air Force Base in California. ... The Compton Gamma Ray Observatory (CGRO) was the most massive instrument ever launched by a NASA Space Shuttle and continues to revolutionize gamma-ray astronomy. ... Space Shuttle Challenger jumps off the launch pad in 1985 to begin a successful mission. ... Space Shuttle Discovery launches while the Space Shuttle Columbia is readied for a future mission. ...

... Editor's choices for the most educational Astronomy Pictures of the Day about orbiting observatories: . ... The trouble is that Earth-bound telescopes must look through the Earth's atmosphere . ... Telescopes which explore the Universe using light beyond the visible spectrum, such as those onboard the Chandra X-ray Observatory need to be carried above the absorbing atmosphere. ... By orbiting above the Earth's atmosphere, the Hubble Space Telescope, pictured above , can get clearer images. ... Index...

... Planets . ... Earth Satellites . ... Looking in the direction of the constellation Cygnus the Swan and launched by NASA in 2009 is the Kepler Space Observatory.Many previous missions searching for exoplanets mainly detected large giant planets, like large hot Jupiters (it is easier to detect larger planets).However KeplerтАЩs main objective is to search for much smaller planets located in a habitable zone which is not too close nor too far from their star; planets which may be just like our Earth. ...

GRANAT is the Russian x-ray sattelite launched to the high apogee orbit (200,000 km) and operated almost for 10 years (1989 -1999) , carrying out four major instruments: French SIGMA coded-mask hard x-ray telescope (30-1000 keV), Soviet ART-P coded-mask telescope (2??-60?? keV), all-sky monitor WATCH (6-150 keV), and a gamma-burst detector PHEBUS . ... Since September 1994, GRANAT is in the survey mode. ... Explore pages devoted to individual GRANAT instruments (including main scientific results): . ...

... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distance to the Moon or 1/100 the distance to the Sun--the spacecraft, too, will need just one year to go around the Sun, and will keep its position between the Sun and the Earth. ...

... With enough velocity, a spacecraft can break loose from the Earth's gravity and enter an orbit around the Sun, like that of a planet. If it then orbits the Sun with the same period as the Earth--one year--it may keep a fixed position relative to Earth. ... If the distance is just right--about 4 times the distance to the Moon or 1/100 the distance to the Sun--the spacecraft, too, will need just one year to go around the Sun, and will keep its position between the Sun and the Earth. ...

Discovery of PSR J0108-1431, the closest known neutron star . ... S. Johnston (RCfTA, University of Sydney, Australia), . M. Bailes (ATNF, CSIRO, Australia), . ... Here we report the discovery of PSR J0108-1431, a pulsar which has the lowest known dispersion measure, 1.83 pc cm^-3. Reasonable models of the interstellar electron density distribution indicate that its distance is less than 100 pc, making it the closest known radio pulsar and probably the closest known neutron star. ...

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... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Although the comet itself never comes dangerously close to the Earth, the particles of dust that it has shed during its many past passages through perihelion found their way into the Earth's atmosphere, appearing as meteors in the cold December sky. ... Animation 1 . ... An Ursid meteor captured by the Armagh Observatory's NE-facing meteor camera in the early morning of 23rd December. ... Meteor Showers Online . ...