Chart basics · Advanced
Topocentric
Measured from a point on Earth's surface rather than its centre.
Seen from the surface, the Moon's position shifts by up to about a degree compared with the geocentric view, because the Moon is close; the planets shift by seconds of arc. Astrological charts conventionally use geocentric positions. The site's sky-watching pages use topocentric ones, because they are about where to look.
- Where sources differ
- A minority of astrologers use topocentric positions; there is also a Topocentric house system, which is a different idea sharing the name.
Sources
Written for Cool Moon Facts in its own words. An astrology source documents what astrologers believe or practise; it does not establish that astrology works.