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Astronomical Reference Systems
Astronomical coordinate systems are organized arrangements for specifying positions of Natural satellite, satellites, planets, stars, galaxy, galaxies, and other celestial objects relative to physical reference points available to a situated observer (e.g. the true horizon and north cardinal direction to an observer situated on the Earth's surface). Coordinate systems in astronomy can specify an object's position in three-dimensional space or plot (graphics), plot merely its direction on a celestial sphere, if the object's distance is unknown or trivial. Spherical coordinates, projected on the celestial sphere, are analogous to the geographic coordinate system used on the surface of Earth. These differ in their choice of fundamental plane (spherical coordinates), fundamental plane, which divides the celestial sphere into two equal sphere, hemispheres along a great circle. Rectangular coordinates, in appropriate Units of measurement, units, have the same fundamental () plane and Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecliptic Equator Galactic Anim
The ecliptic or ecliptic plane is the orbital plane of the Earth's orbit, Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the fixed stars, background of stars. The ecliptic is an important Plane of reference, reference plane and is the basis of the ecliptic coordinate system. Sun's apparent motion The ecliptic is the apparent path of the Sun throughout the course of a year. Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth did no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
