Is Phoebe A Kuiper Belt Object?Phoebe is a 200 km scale irregular satellite of Saturn. With a retrograde orbit (inclination 178 deg), Phoebe cannot have formed in a Saturn-associated accretion disk and, instead, is inferred to have been captured from an independent orbit around the Sun... The two main possibilities are that... Phoebe was captured from heliocentric orbit near Saturn, probably in association with planet formation itself... OR... Phoebe was captured from a more distant reservoir, possibly the Kuiper Belt. We do not possess any way to decide clearly between these possibilities. Recently, Kuiper Belt capture has been widely publicised and two (not wholly convincing) strands of evidence have been supplied.
by David Jewitt
Last updated Jun 2006