In astronomy and spaceflight, a lunar orbit is an orbit by an object around Earth's Moon. In general these orbits are not circular. When farthest from the Moon a spacecraft is said to be at apolune, apocynthion, or aposelene. When closest to the Moon it is said to be at perilune, pericynthion, or periselene. These derive from names or epithets of the moon goddess.
Lunar orbit insertion is an orbit insertion maneuver used to achieve lunar orbit.
Low lunar orbit is an orbit below 100 km altitude. These have a period of about 2 hours. From Wikipedia
