In addition to the eight traditional planets, there are several Dwarf Planets in the Solar System. Like the eight main planets, they are round and orbit the Sun. However, what makes them Dwarf Planets is their size and also the fact that they haven't "cleared the neighbourhood" of their orbits. This could mean that they orbit the Sun in an asteroid belt or the route they take around the Sun crosses the orbit of another object also orbiting the Sun. The most famous Dwarf Planet is Pluto, which since its discovery in 1930, was recognised as the ninth planet in the Solar System until being reclassified in August 2006. Other objects recognised as Dwarf Planets are Ceres, which orbits the Sun between Mars and Jupiter, and Eris, which, like Pluto, orbits the Sun beyond Neptune. More Dwarf Planets are expected to be added to this list over the coming years.