List of dwarf planets in the solar system.
Official Dwarf Planets
- Ceres - First body in the asteroid belt discovered, at first thought to be the eight planet, then redesignated the largest asteroid, and later a dwarf planet due to its roundness. It is the only dwarf planet in the asteroid belt. Composed mainly of water ice. Second destination for the Dawn spacecraft.
- Pluto - Discovered after an extensive search for Planet X. Initially thought to be Earth size and dubbed the ninth planet, then continuously reduced in size as its brightness became clear and its large moon was discovered, until another object Eris was discovered in its region of space that was more massive than it, when it was demoted to a Dwarf Planet status. Considered by some a double dwarf planet due to its large moon. Also has three tiny moons and could support a ring system. First Kuiper Belt object discovered, in 2:3 orbital resonance with Neptune. Target of New Horizons spacecraft.
- Eris - The second dwarf planet found in the Kuiper Belt, briefly referred to as the 10th planet. Being more massive than Pluto and about the same size, Eris' discovery lead to a new definition of the word planet and reclassified itself, Pluto, and Ceres and Dwarf Planets. Originally codenamed "Xena", it is now named after the Greek goddess of discord. Furthest body detected at time of discovery, when it was near its aphelion. Much more dense than Pluto (and thus composed of more rock) and further away, but has about the same surface composition. Largest scattered disc object, which depending on the definition used, would also be the largest Kuiper Belt object. Color appears greyish, unlike Pluto, because it is far enough for Methane to condense on all parts of its surface, including low albedo features. Has one small moon, Dysnomia.
- Haumea - Fifth dwarf planet recognized. Discovery claimed by two teams, one was able to claim discovery, while another to name the object. Originally code named Santa, now named after a goddess, whose body was broken up to form the Hawaiian island. Though to have broken up and formed two satellites (made of pure water ice), in addition to a family that shares its orbit, the first such family found in the Kuiper Belt. Originally classified as a classic Kuiper Belt object, it has now been shown to be in 7:12 orbital resonance with Neptune. In a highly inclined orbit similar to Makemake and the third apparent brightest body in the Kuiper Belt. Spins so fast (4 hours), that it is shaped somewhat like a cigar, yet remains in hydrostatic equilibrium. Likely mostly rock with a thin layer of water ice, unusual in that it doesn't show signs of Methane. Surface is mottled, with a large red spot, possibly a crater, though not as extreme as Pluto. Its surface appears to by crystalline ices.
- Makemake - Largest object in the Classical Kuiper Belt and third largest dwarf planet, three quarters or as big as Pluto. Second apparent brightest Kuiper Belt object in the solar system, it escaped detection for a while due to its high inclined orbit and because it was at its furthest point when discovered. The only undetected Dwarf Planet that Clyde Thombough could have detected, though it was near the galactic plain at the time. Originally code named Easterbunny, officially named after a creator and fertility god of Easter Island in Hawaii. Located in the center of the Kuiper Belt. Reddish in color, surface likely composed of frozen methane. Has no moons.
Prime Dwarf Planet Candidates
- Orcus - Ss:Orcus
- Huya - Ss:Huya
- Ixion - Ss:Ixion
- Varuna - Ss:Varuna
- Quaoar - Dwarf planet candidate orbiting, about 900 km in diameter.
- Sedna - Dwarf planet candidate orbiting in a detached orbit around the Sun. Orbit is not affected by Neptune. Its year is 12,000 years and size thought to be two thirds that of Pluto's.
- 1996 TL66 - Ss:1996 TL66
- 2002 AW197 - Ss:2002 AW197
- 2002 TC302 - Ss:2002 TC302
- 2007 OR10 - Ss:2007 OR10