• Eris
  • Sedna
  • dwarf planets
  • 2003EL61

Dwarf planets

A selection of sites and links about dwarf planets in general and about some of the largest dwarf planets recently discovered in our survey at Palomar Observatory.
  • How many dwarf planets are there? (And what are they?)

    This continuously updating list records the likely and possible dwarf planets discovered in our solar system so far.

  • The dwarf planet page

    What is a dwarf planet? Explanations of this new class written at the time of the new definition along with a complete list of the likely candidates that met the criteria for dwarf planethood at that time.

  • The eight planets

    An explanation of why astronomers decided that Pluto should no longer be considered a planet and why eight is a good number of planets.

  • Eris

    The largest dwarf planet, and the object whose discovery prompted the decision to reclassify all of these objects, including Pluto, as dwarf planets.

  • A Requiem for Xena

    A farewell to the former planet formerly known as Xena, now officially known as the dwarf planet named Eris.

  • 2003 EL61 = Haumea

    Information about Haumea, a rapidly spinning Pluto-sized football-shaped ice-coated deformed rock in the outer solar system with a family of icy debris around it.

  • Sedna

    the first of a new class of objects beyond the Kuiper belt and a fossilized record from the birth of the solar system.

  • Orcus

    Pluto's slightly smaller twin.

  • Quaoar

    The first to be discovered (in 2002) of the truly gigantic Kuiper belt objects. Named for the creation deity of the Tongva tribe.

  • Thoughts on the planet debate

    Commentary written while astronomers were debating the new definition of the word "planet."