<P> Trojans are populations that share an orbit with a larger planet or moon, but do not collide with it because they orbit in one of the two Lagrangian points of stability, L4 and L5, which lie 60 ° ahead of and behind the larger body . </P> <P> The most significant population of trojans are the Jupiter trojans . Although fewer Jupiter trojans have been discovered (As of 2010), it is thought that they are as numerous as the asteroids in the asteroid belt . Trojans have been found in the orbits of other planets, including Venus, Earth, Mars, Uranus, and Neptune . </P> <P> Near - Earth asteroids, or NEAs, are asteroids that have orbits that pass close to that of Earth . Asteroids that actually cross Earth's orbital path are known as Earth - crossers . As of June 2016, 14,464 near - Earth asteroids are known and the number over one kilometer in diameter is estimated to be 900--1,000 . </P> <P> Asteroids vary greatly in size, from almost 7006100000000000000 ♠ 1000 km for the largest down to rocks just 1 meter across . The three largest are very much like miniature planets: they are roughly spherical, have at least partly differentiated interiors, and are thought to be surviving protoplanets . The vast majority, however, are much smaller and are irregularly shaped; they are thought to be either surviving planetesimals or fragments of larger bodies . </P>

The asteroids that cross the orbit of earth belong to a group called the