The Asteroid Belt
Facts About The Asteroid Belt:
Asteroids are small bodies including minor planets and dwarf planets. They can appear anywhere in the Solar System but are concentrated in the asteroid belt and inner regions. They are distinct from comets which are icy objects originating further out in the Solar System.
The asteroid belt is located between the orbits of Mars and Jupiter.
We know of hundreds of thousands of asteroids in the belt, but there are probably millions.
Over 200 asteroids are known to be larger than 100 km wide. There are probably about a million that are larger than 1 km.
About half the mass of the belt is contained in the four largest asteroids: Ceres, Vesta, Pallas and Hygiea.
Most of the asteroid belt is empty. If you stood on an asteroid you probably couldn't see any others except as faint star-like objects. About a dozen robotic spacecraft have been through the asteroid belt without hitting anything.