spacetoday.net: Volcanism possible in Kuiper Belt

Posted: Sun, Dec 12, 2004, 7:42 AM ET (1242 GMT)
Quaoar illustration (NASA and G. Bacon (STScI))

Planetary scientists have found evidence that objects in the Kuiper Belt, the realm of icy objects beyond the orbit of Neptune, can experience a kind of volcanic activity. In a paper published in the current issue of the journal Nature, scientists report detecting ammonia hydrate and the crystalline form of water ice on the surface of Quaoar, the largest KBO discovered to date. Since these compounds should be destroyed in just a few million years by irradiation, scientists believe that they were emplaced there recently by cryovolcanism, a type of volcanism that involves molten ice rather than rock. They also note that impacts could have also exposed these ices had they previously been protected under its surface. The heat required to support volcanism, scientists argue, would likely come from the radioactive decay of elements like uranium that may exist in Quaoar's core.