Eris Archives -
In January 2005, Mike Brown announced the discovery of another object from the Kuiper belt, even larger than Pluto. This dwarf planet (plutoid) provisionally named 2003 UB313 or Xena, was recently officially called, Eris.
Ceres was classified as a dwarf planet, but it’s also considered an asteroid. Discovered on January 1, 1801 by Giuseppe Piazzi, Ceres has a diameter of 950 km and it is by far the largest and most massive asteroid from the asteroid belt, containing one third of the total mass of the asteroid belt.