Haumea (pronounced how-may-a) is a rugby ball-shaped dwarf planet that was discovered in December 2004.
It's around one-third the mass of Pluto. We've never taken close observations of Haumea, but because of the way it reflects sunlight astronomers think that it's shaped like a rugby ball, with one of its axes twice as long as the other. The odd shape is caused by its very fast rotation rate - it spins once every 4 hours.
Haumea has two known moons, named Hiʻiaka and Namaka, and the surface temperature on all three is thought to be around -240°C (or 32K).
Haumea is also a type of plutoid - a dwarf planet that circles the Sun beyond the orbit of Neptune.
|Facts and Figures||Ceres||Pluto||Haumea||Makemake||Eris|
|Orbital distance (AU)1||2.77||39.5||43.1||45.8||67.7|
|Mass (Earth Masses)2||0.00016||0.00213||0.0007||0.0007||0.003|
|Year Length (Earth Years)||4.6||248.5||283.3||309.9||557|
|Day Length (Earth Days)||0.38||6.39||0.16||Unknown||Unknown|
|Surface Gravity (g)3||0.003||0.04||0.044||0.05||0.08|
|Surface Temperature||about -105°C||about -230°C||about -240°C||about -243°C||about -240°C|
|Number of moons||0||3||2||0||1|