Thursday, June 24, 2004

Phoebe Update


The initial analysis from Cassini's Phoebe flyby is in. As suspected by astronomers, Phoebe appears to be a Kuiper Belt Object, one of the "leftover bits" from the earliest period of solar system formation. Most of these small planetoids were flung out beyond the orbit of Neptune by gravitational interaction with the larger planets.

Phoebe, however, managed to stick around. She got herself stuck in a distant and eccentric orbit of Saturn and stayed there unheeded and undisturbed for billions of years. Last week, Cassini became the first Earth spacecraft to observe one of these planetary "oddballs" close up. Phoebe did not disappoint.