A number of small bodies that revolve around the sun between the orbits of Mars and Jupiter in a zone between 1.7 and 4.0 astronomical units from the sun (the asteroid belt). The size of the bodies varies from the largest, Ceres (with a diameter of 933 km), to objects less than 1 km in diameter. It is estimated that there are about 10 bodies with diameters in excess of 250 km and some 120 bodies with diameters over 130 km. Ceres is now classified as a dwarf planet (see planet). Other asteroids are classified as SSSBs (small solar system bodies). See Solar System (Feature).