Ceres

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/Justin Cowart
Ceres is a dwarf planet that is the largest object orbiting within the asteroid belt.
Ceres is a dwarf planet that is the largest object orbiting within the asteroid belt.
In addition to the eight planets in our Solar System, there are a number of Dwarf Planets that do not meet all the criteria required to be a full-blown planet, in the sense that they are not large enough to have cleared their orbits of other similar objects.