|
orbit
orbit in astronomy, path in space described by a body revolving about a second body where the motion of the orbiting bodies is dominated by their mutual gravitational attraction. Within the solar system, planets, dwarf planets, asteroids, and comets orbit the sun and satellites orbit the planets an...
Read more
|
|
orbiting observatory
orbiting observatory research satellite designed to study solar radiation, electromagnetic radiation from distant stars, the earth's atmosphere , or the like. Because the atmosphere and other aspects of the earth's environment interfere with astronomical observations from the ground, especiall...
Read more
|
|
molecular orbital theory
molecular orbital theory detailed explanation of how electrons are distributed in stable molecules . In the simpler valence theory of the chemical bond , each atom in a molecule is assumed to retain its own electrons. Even when electrons are shared, as in the covalent bond, it is possible to id...
Read more
|
|
Orbiting Astronomical Observatory
Orbiting Astronomical Observatory (OAO), series of four orbiting observatories (see observatory, orbiting ) launched between 1966 and 1972 by the National Aeronautics and Space Administration (NASA) to provide astronomical data in the ultraviolet and X-ray wavelengths filtered out by the earth's a...
Read more
|
|
Orbiting Solar Observatory
Orbiting Solar Observatory (OSO), series of eight orbiting observatories (see observatory, orbiting ) launched between 1962 and 1971 by the National Aeronautics and Space Administration (NASA) to study the sun in the ultraviolet and X-ray wavelengths filtered out by the earth's atmosphere. The thi...
Read more
|
|
inclination
inclination in astronomy, the angle of intersection between two planes, one of which is an orbital plane. The inclination of the plane of the moon's orbit is 5°9′ with respect to the plane of the ecliptic (the plane of the earth's orbit around the sun). The inclination of the plane of the...
Read more
|
|
apsis
apsis (pl. apsides), point in the orbit of a body where the body is neither approaching nor receding from another body about which it revolves. Any elliptical orbit has two apsides. At the perigee the moon or other satellite is as close as it ever gets to the earth, and it begins to move away; at...
Read more
|
|
Helene
Helene , in astronomy, one of the named moons, or natural satellites, of Saturn . Also known as Saturn XII (or S12), Helene is an irregularly shaped (nonspherical) body measuring about 22 mi (36 km) by 20 mi (32 km) by 18 mi (30 km); it orbits Saturn at a mean distance of 234,500 mi (377,400 km) an...
Read more
|
|
Telesto
Telesto , in astronomy, one of the named moons, or natural satellites, of Saturn . Also known as Saturn XIII (or S13), Telesto is an irregularly shaped (nonspherical) body measuring about 21 mi (34 km) by 17 mi (28 km) by 16 mi (26 km); it orbits Saturn at a mean distance of 183,093 mi (294,660 km)...
Read more
|
|
space shuttle
space shuttle Re-usable rocket-powered US spacecraft. The main part of the shuttle, the orbiter (of which four have been built, Columbia, Challenger, Discovery, and Atlantis), looks like a bulky jet aircraft with swept-back wings. It ferries people and equipment between the ground and Earth orbit. ...
Read more
|