Haumea

Haumea is a celestial body orbiting the sun beyond Neptune. It is classified as a dwarf planet—a body massive enough to adopt a roughly spherical shape through its own gravity, but one that has not cleared its orbital path of other debris. It belongs to the Kuiper Belt, the region of ice and rock beyond the inner Solar System.

Haumea's most distinctive feature is its shape: it rotates so rapidly on its axis that it is flattened, resembling an egg rather than a sphere. It has two known moons, and has been found to possess a ring around it—an unusual characteristic for bodies of its type.

Discovery and naming

Haumea was discovered in the early 2000s. The discovery was claimed by two research teams—an American team led by Mike Brown and a Spanish team. The name comes from Haumea, a Hawaiian deity of fertility and childbirth. The two moons were given names derived from that mythology.

Physical characteristics

Haumea's rotation is among the fastest of the large bodies in the Solar System, with a rotation period of only a few hours. This rapid rotation has pulled its shape outward at the sides, making it longer along one axis than another. Its surface shows signs of water ice and reflects light strongly. Its dense composition at the surface suggests a rocky interior beneath an outer layer of ice.

Moons and ring

Two moons orbiting Haumea have been identified, one larger than the other. During observations in the mid-2010s, when Haumea passed in front of a star, data gathered revealed the presence of a ring around it—the first time a ring was detected around a body beyond the giant planets. There is also a group of smaller bodies with similar characteristics to Haumea, thought to have resulted from an earlier collision.

Orbit around the sun

Haumea's orbit around the sun takes hundreds of Earth years and lies at a distance well beyond Neptune. The orbit is elongated and not perfectly circular, causing the distance from the sun to vary significantly during the orbit. No spacecraft has visited it so far; most of the current information has been gathered from Earth-based telescopes and space-based observations.