apparent orbit
51Mercury (planet) — Mercury  ☿ …
52Space elevator — A space elevator for Earth would consist of a cable anchored to the Earth s equator, reaching into space. By attaching a counterweight at the end (or by further extending the cable upward for the same purpose), the center of mass is kept well… …
53star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
54Retrograde and direct motion — Direct motion is the motion of a planetary body in a direction similar to that of other bodies within its system, and is sometimes called prograde motion. Retrograde motion is motion in the opposite direction. In the case of celestial bodies,… …
55Solar eclipse — A solar eclipse occurs when the Moon passes between the Sun and the Earth so that the Sun is wholly or partially obscured. This can only happen during a new moon, when the Sun and Moon are in conjunction as seen from the Earth. At least two and… …
56Hipparchus — (Greek polytonic|Ἵππαρχος; ca. 190 BC ndash; ca. 120 BC) was a Greek astronomer, geographer, and mathematician of the Hellenistic period.Hipparchus was born in Nicaea (now Iznik, Turkey), and probably died on the island of Rhodes. He is known to… …
57Venus — This article is about the planet. For other uses, see Venus (disambiguation). Venus   …
58Mars — This article is about the planet. For other uses, see Mars (disambiguation) …
59mechanics — /meuh kan iks/, n. 1. (used with a sing. v.) the branch of physics that deals with the action of forces on bodies and with motion, comprised of kinetics, statics, and kinematics. 2. (used with a sing. v.) the theoretical and practical application …
60solar system — the sun together with all the planets and other bodies that revolve around it. [1695 1705] * * * The Sun, its planets, and the small bodies (see asteroid, Centaur object, comet, Kuiper belt, meteorite, and Oort cloud) interplanetary dust and gas… …
