The outermost known moon of Saturn.
Phoebe is an oddball, orbiting in a retrograde motion, in an eccentric orbit (e = 0.16326) that is much closer to the ecliptic of the Solar System rather than Saturn's equatorial plane. It orbits at a distance of 13,000,000 km from Saturn, taking 550 Earth days to complete an orbit. Its diamater is only 220 km. Voyager 2 imaged the satellite on its way past Saturn in 1981 and found that it is roughly circular in shape and quite dark, reflecting only 6% of the sunlight it receives, but little detail was resolved.
It is believed that Phoebe is a captured asteriod and did not form with the rest of the moons of Saturn. It is thought that Phoebe might be composed of the original solids from the solar nebula, as it was not big enough to heat up and cause its chemical composition to change, and as such is not just another lump of rock. The Cassini probe will get a closer look in 2004 when it passes Phoebe at 50,000 km on its way into orbit around Saturn.