Trojan (celestial body)

Objects sharing the orbit of a larger one

In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger body, remaining in a stable orbit approximately 60° ahead of or behind the main body near one of its Lagrangian points L4 and L5. Trojans can share the orbits of planets or of large moons. Trojans are one type of co-orbital object.

From Wikipedia, under CC BY-SA. More on occurri.