Astrophysics (index)about


(ecliptic plane)
(path of the Sun on the celestial sphere as seen from Earth)

The ecliptic (or ecliptic plane) is the plane of the Earth's orbit around the Sun. From Earth, over the course of a year, the Sun appears to be moving in a line (a great circle) around the celestial sphere and the term ecliptic refers to that line around the sky, which constitutes a plane viewed from a point on it. The line can be tracked by watching which stars are behind the Sun as it sets. This line passes through the well-known list of constellations used in astrology.

The orbits of the solar system planets and many of the minor planets are not far from the ecliptic, with long-period comets less so.

A spherical coordinate system based upon the ecliptic is the ecliptic coordinate system.

In contrast, the celestial equator is the plane through Earth's equator.

(coordinates,celestial sphere,Sun,Earth)

Referenced by:
celestial coordinate system
celestial equator
ecliptic coordinate system
irregular moon
Kuiper Belt (K Belt)
long-period comet
Oort Cloud
orbital element
orbital inclination
zodiacal light