- 行业: Astronomy
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Planetary Science Research Discoveries (PSRD) is an educational site sharing the latest research by NASA-sponsored scientists on meteorites, asteroids, planets, moons, and other materials in our Solar System. The website is supported by the Cosmochemistry Program of NASA's Science Mission ...
U. S. Mission consisting of two spacecraft launched in 1977 to explore Jupiter, Saturn, Uranus, Neptune, and their moons, rings, and magnetic environments. It took 2 years for the crafts to reach Jupiter. The last image was taken in 1989 and now both crafts are headed for the outer Solar System.
Industry:Astronomy
The angle between the lines of sight to the Sun and to the celestial body in question.
Industry:Astronomy
An element with atomic number 1; symbol: H. It is the most abundant element in the Solar System, making up 90 percent of the Sun. Hydrogen, carbon, nitrogen, and oxygen are essential for life.
Industry:Astronomy
A course-grained igneous rock rich in the minerals olivine, pyroxene, and plagioclase feldspar.
Industry:Astronomy
Movements of mantle material, laterally or in upward-downward directions, due to heat variations.
Industry:Astronomy
Jupiter's four largest moons: Io, Europa, Ganymede, and Callisto, discovered independently by Galileo Galilei and Simon Marius in 1609-1610.
Industry:Astronomy
U. S. Mission to study Jupiter's atmosphere, moons, and magnetosphere. The Galileo spacecraft was carried into space and released in 1989 by the shuttle Atlantis. It used its own rocket booster to leave Earth orbit. The Galileo spacecraft arrived at Jupiter in 1995 and completed its two-year primary mission before going on to explore Europa. The 14-year mission ended in 2003. Project Galileo website.
Industry:Astronomy
U. S. Mission launched in August, 2001 to observe and collect solar wind samples and return them to Earth. Sample collections were obtained at the L1 point, approximately one million miles from Earth where the gravities of Earth and Sun are balanced. The sample capsule landed back on Earth in September, 2004 in an unexpected crash after its deceleration sensor failed and the parachutes did not open. Nevertheless, solar wind samples were recovered, cleaned, and stored successfully and are now being studied meticulously. Genesis Mission webpage.
Industry:Astronomy
The geologic history of Earth's Moon has been divided into five broad time periods, or systems. From oldest to youngest, these are pre-Nectarian, Nectarian, Imbrian, Eratosthenian, and Copernican. These systems are defined by the number of impact craters on the ground surface (more craters = older surface) correlated to the absolute ages determined for the lunar rock samples returned to Earth by the U. S. Apollo missions and unpiloted Soviet Luna missions. The Eratosthenian system extends from 3. 2 billion to 1. 1 billion years ago.
Industry:Astronomy
