The main asteroid belt extends from 2.15 to 3.3 astronomical units (255 to 600 million km) from the sun- between mars (1.5 AU)

         and Jupiter (5.2 AU)-and may contain over a million objects bigger than 1 km across the largest being Ceres (1003 km) Pallas ( 608 km)

         and Vesta (538 km). The belt appears to have originated as a system of perhaps 50 large bodies in the 100 to 1000 km size range these

          accreted during the  formation of the solar system  and there a