9A. DWARF PLANET (ASTEROID BELT) – CERES Ceres is the only dwarf planet lying within the asteroid belt – meaning between Mars and Jupiter. It was discovered in 1801 and is the only object in the belt rounded by its own gravity. Here’s how big it is compared to the Earth and Moon. It is thought to make up about one third of the mass of the asteroid belt. A spacecraft we sent there (2015) has observed lots of bright spots. Scientists think they’re caused by ice or salts reflecting sunlight. Ceres is heavily cratered. Ceres is cold but not crazily so. Highs are thought to be around -38 celcius which means there are colder places on Earth. At this temperature ices can become unstable leading to a less shiny planet than other moons, for example, deeper in the solar system.