Chilly Quaoar May Have Had Warmer Past

The Journal Nature is reporting that the planetoid Quaoar may have had a warmer past.  The folowing paper found that Quaoar had crystalline ice implying a warmer past than expected. David Jewitt, one of the paper's authors put it this way:

"At that temperature [50K, the surface temperature of Quaoar], the ice on Quaoar should be amorphous, but it is not," says David Jewitt, an astronomer from the Institute for Astronomy in Honolulu, Hawaii.

Why Quoaoar has crystalline water ice is still somewhat of a mystery. Either the radioactive decay of elements such as Uranium or Thorium are heating the planetoid, or the same decay may have triggered 'cryogenic volcanism'. This latter volcanism could bring wamer crystalline water ice to the surface.