Quaoar

A relatively large body, potentially belonging to the classification of a dwarf planet, that orbits the Sun beyond Neptune in region known as the Kuiper Belt. Bodies of this kind, known as cubewanos, are conventionally named for creator deities from different mythologies, and Quaoar takes its name from such a being from the tales of the Tongva Native American culture. There is no standard pronunciation of its name: the simple kwa-war is commonplace, but the name is also sometimes pronounced kwa-o-ar.

When it was discovered in 2002, Quaoar was the largest such body known, and it was thus given the significant designation '50000' to mark the event (though it has since been surpassed by the discovery of several other, larger, objects in the outer Solar System). With a diameter of more than a thousand kilometres, Quaoar is roughly half the size of the dwarf planet Pluto.

Quaoar orbits the Sun at a distance of 43.16 AU, following an orbital path that is close to circular and also close to the plane of the Solar System. This is relatively unusual for a body in this region of space: similar objects commonly exhibit highly eccentric and inclined orbits.

Physically, Quaoar is an approximate spheroid, but elongated into an ellipsoid. Its longest axis measures 1,236 km, while its shortest (the axis around which it rotates) measures 932 km.. It has a generally reddish colouration, and there is evidence for cryovolcanic activity, with liquid ice being thrust out from the interior and spreading across the surface. Quaoar has a single known moonlet, a tiny object named Weywot for the son of Quaoar in the Tongva mythology. Within Weywot's orbit, Quaoar also posseses a ring system, a pair of narrow tenuous rings of material orbiting Quaoar at approximately 2,500 km and 4,000 km respectively.