The Asteroid Belt
Some examples of asteroids in the main belt. Image Credit: NASA/JPL-Caltech/JAXA/ESA
The strong gravitational attraction of Jupiter prevented the formation of planets in the region that is currently occupied by the main asteroid belt. But the drama of the arrested planetary development turns out to have fortunate consequences: The asteroids in the main belt preserve the original state of the young solar system.
The asteroids differ in shape and size. The largest objects reach over 500 kilometers in size. Ceres, with its nearly 1000 km diameter, is the only object in the asteroid belt classified as a "dwarf planet". Dwarf planets are objects in orbit around the Sun that have contracted into the form of a sphere due to their large mass. The difference to "normal" planets is that dwarf planets were not able to clear their orbit of other objects.