Ecliptic coordinate system

Not to be confused with Elliptic coordinate system.

In astronomy, the ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations[1] of Solar System objects. Because most planets (except Mercury) and many small Solar System bodies have orbits with only slight inclinations to the ecliptic, using it as the fundamental plane is convenient. The system's origin can be the center of either the Sun or Earth, its primary direction is towards the March equinox, and it has a right-hand convention. It may be implemented in spherical or rectangular coordinates.[2]

Earth-centered ecliptic coordinates as seen from outside the celestial sphere.
  Ecliptic longitude; measured along the ecliptic from the March equinox
  Ecliptic latitude; measured perpendicular to the ecliptic
  Celestial equator
A full globe is shown here, although high-latitude coordinates are seldom seen except for certain comets and asteroids.
  1. ^ Cite error: The named reference Cunningham1985 was invoked but never defined (see the help page).
  2. ^ Nautical Almanac Office, U.S. Naval Observatory; H.M. Nautical Almanac Office, Royal Greenwich Observatory (1961). Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac. H.M. Stationery Office, London (reprint 1974). pp. 24–27.