An Etymological Dictionary of Astronomy and Astrophysics

A special case of the → three-body problem in which the
→ mass of one of the bodies is negligible compared to that of the two others. If the relative motion of the two massive components is a circle, the situation is referred to as the → circular restricted three-body problem. An example would be a space probe moving in the → gravitational fields of the → Earth
and the → Moon, which revolve very nearly in circles about their common → center of mass.

See also: → restrict; → three; → body; → problem.