Objects in the main asteroid belt vary greatly in size, from a diameter of 950 kilometers for the dwarf planet Ceres and over 500 kilometers for the asteroids 2 Pallas and 4 Vesta down to rocks just tens of meters across. Various classes of asteroid have been discovered outside the main asteroid belt. Near-Earth asteroids have orbits in the vicinity of Earth's orbit. Trojan asteroids are gravitationally locked into synchronisation with Jupiter, either leading or trailing the planet in its orbit. __
