celestial+sphere
21sphere — (n.) 1530s, restored spelling of M.E. spere (c.1300) space, conceived as a hollow globe about the world, from O.Fr. espere (13c.), from L. sphæra globe, ball, celestial sphere, from Gk. sphaira globe, ball, of unknown origin. Sense of ball, body… …
22celestial equator — n. the great circle formed on the celestial sphere by extending the plane of the earth s equator: see DECLINATION …
23celestial pole — n. either of two points on the celestial sphere where the extensions of the earth s axis would intersect: see DECLINATION …
24Celestial spheres — Not to be confused with celestial sphere. For other uses, see Celestial (disambiguation). Geocentric celestial spheres; Peter Apian s Cosmographia (Antwerp, 1539) …
25Celestial pole — The north and south celestial poles and their relation to axis of rotation, plane of orbit and axial tilt …
26Celestial coordinate system — For other uses of Celestial , see Celestial (disambiguation). Orientation of Astronomical Coordinates Orientation of the galactic, ecliptic and equatorial coordinate systems, projected on the celestial sphere, showing the galactic equator (black) …
27Sphere (disambiguation) — A sphere is an object shaped like the surface of a ball, but can be used to refer to a ball shaped object, as well as a sphere like or annular region or shell. Additionally, it has several metaphorical uses.In mathematics: * Sphere, the set of… …
28Celestial equator — The celestial equator is a great circle on the imaginary celestial sphere, in the same plane as the Earth s equator. In other words, it is a projection of the terrestrial equator out into space. As result of the Earth s axial tilt, the celestial… …
29celestial meridian — Semi–great circles produced by projecting the earth’s meridian onto the celestial sphere. Each earth’s meridian has its corresponding celestial meridian. The celestial meridian of any place on the earth is the great circle of the celestial sphere …
30sphere — sphereless, adj. spherelike, adj. /sfear/, n., v., sphered, sphering. n. 1. Geom. a. a solid geometric figure generated by the revolution of a semicircle about its diameter; a round body whose surface is at all points equidistant from the center …
