This illustration demonstrates the orbit of 2010 TK7, the first known Earth Trojan asteroid, discovered by NEOWISE, the asteroid-hunting portion of NASA's WISE mission.
Trojan asteroids are asteroids that orbit near one of the two trojan points of a planet. A trojan moon is a moon residing at the trojan point of another (larger) moon. Trojan planets are theoretical planets that orbit at the trojan points of other planets.
Saturn has the only known trojan satellites: Saturn's moon Tethys has two trojan moons (Telesto and Calypso), and Dione also has two trojan moons (Helene and Polydeuces).