Appulse

thumb|The Moon and [[Venus in the evening sky on three consecutive days. The centre image shows an appulse between the two objects.]]

Appulse is the least apparent distance between one celestial object and another, as seen from a third body during a given period. Appulse is seen in the apparent motion typical of two planets together in the sky, or of the Moon to a star or planet while the Moon orbits Earth, as seen from Earth. An appulse is an apparent phenomenon caused by perspective only; the two objects involved are not necessarily near in physical space.