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Ceres is the largest object in the asteroid belt, which is located between the orbit of Mars and Jupiter. At first it was designated as a planet, but after much debate it was classified in the same family as Pluto- a dwarf planet (what is a dwarf planet?).
Ceres is the smallest of the dwarf planets, and while all others lie in the Kuiper Belt, Ceres does not. Its mass is nearly a full third of the entire asteroid belt, and is about 950 km in diameter. In contrast our moon is 3476.2 km in diameter.
Quoted from the Wiki article on Ceres:
The surface of Ceres is relatively warm. The maximum temperature with the Sun overhead was estimated from measurements to be 235 K (about −38 °C) on May 5, 1991.[13] Taking into account also the heliocentric distance at the time, this gives an estimated maximum of about 239 K at perihelion. There are some indications that Ceres may have a tenuous atmosphere and water frost on the surface.[17] Ultraviolet observations by IUE spacecraft detected statistically significant hydroxide water vapour near the Cererean north pole.[17]
Peter Thomas of Cornell University has proposed that Ceres has a differentiated interior;[3] its oblateness appears too small for an undifferentiated body, which indicates that it consists of a rocky core overlain with an icy mantle.[3] This mantle of thickness from 120 to 60 km could contain 200 million cubic kilometers of water (16–26 percent of Ceres by mass; 30–60 percent by volume), which is more than the amount of fresh water on the Earth.[43] This result is supported by the observations made by Keck telescope in 2002 and by evolutionary modelling.[4][44]
*Edit 03-06-09: I just found this link on Ceres today, and thought I'd post it here:
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