The Asteroid Belt consists of millions of chunks of rock orbiting the Sun. They range in size from tiny bits of rock to ones so big that they would be classed as planets if they orbited the Sun on their own. Ceres, the largest object within the belt has a diameter of nearly 1,000 km, although it is now classed as a dwarf planet rather than an asteroid because its gravity is powerful enough to make it round. It is possible that a planet would have formed where the belt is now, but Jupiter's powerful gravity prevented one from doing so.

A collage of some typical asteroids.

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