Some astronomers believe that asteroids are planets that did not quite form, and are often called minor planets or planetoids.
Asteroids move in orbits around the Earth and many other planets, and the Sun .
The biggest orbit is the Asteroid Belt located in a region between Mars and Jupiter , with more than 3000 asteroids orbiting the Sun in a slightly elliptical or oval-shaped path, in the same direction as the planets. For a complete orbit around the Sun, the Asteroid Belt travels three to six Earth years on this path. In space, there are more than 4000 asteroids known and recorded by astronomers, and there are still thousands more to be discovered in outer space. Astronomers know the orbits of known asteroids well enough to predict their locations far in advance. Saturn 's rings are actually tiny asteroids travelling in an orbit around Saturn.