near-circular orbit
71Mars Reconnaissance Orbiter — Conceptual image depicting the Mars Reconnaissance Orbiter in an elliptical low planet orbit around Mars Operator NASA / JPL Major contractors Lockheed Ma …
72Lunar Prospector — LunarOrbiter Name=Lunar Prospector Organization=NASA Contractors=Discovery Program MissionType=Planetary Science LaunchDate=January 7, 1998 at 02:28:44 UTC LaunchVehicle=Athena II MissionHighlight=Entered lunar orbit January 11, 1998, 10:28 UTC… …
73Bohr model — In atomic physics, the Bohr model created by Niels Bohr depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus mdash;similar in structure to the solar system, but with… …
74Oort constants — The Oort constants (discovered by Jan Oort) A and B are empirically derived parameters that characterize the local rotational properties of our galaxy, the Milky Way, in the following manner: where V0 and R0 are the rotational velocity and… …
75Celestial mechanics — is the branch of astrophysics that deals with the motions of celestial objects. The field applies principles of physics, historically classical mechanics, to astronomical objects such as stars and planets to produce ephemeris data. Orbital… …
76magnetism — /mag ni tiz euhm/, n. 1. the properties of attraction possessed by magnets; the molecular properties common to magnets. 2. the agency producing magnetic phenomena. 3. the science dealing with magnetic phenomena. 4. strong attractive power or… …
77mathematics — /math euh mat iks/, n. 1. (used with a sing. v.) the systematic treatment of magnitude, relationships between figures and forms, and relations between quantities expressed symbolically. 2. (used with a sing. or pl. v.) mathematical procedures,… …
78Satellite — This article is about artificial satellites. For natural satellites, also known as moons, see Natural satellite. For other uses, see Satellite (disambiguation). An animation depicting the orbits of GPS satellites in medium Earth orbit …
79Escape velocity — In physics, escape velocity is the speed where the kinetic energy of an object is equal to the magnitude of its gravitational potential energy, as calculated by the equation,:U g = frac{ Gm 1m 2}{r}.It is commonly described as the speed needed to …
80Outer space — For other uses, see Outer space (disambiguation). The boundaries between the Earth s surface and outer space, at the Kármán line, 100 km (62 mi) and exosphere at 690 km (430 mi). Not to scale Outer space is the void that exists beyond any… …
