Photographs from Cassini's flyby of Saturn's moon Phoebe have revealed a battered body, with an interesting past. Its face is pock-marked with craters ranging from 80 kilometers across to less than one kilometer, with variations in colour suggesting it contains plenty of ice.
The larger impact sites have prompted speculation that collisions in Phoebe's past could have blasted off enough material to have formed Saturn's smaller retrograde moons.
The brighter craters are most likely the newer impacts. Each collision would have blasted off surface material, and exposed brighter material, possibly ice, below the surface. There is more evidence for this theory on the crater walls: darker material seems to have slid down slope, exposing more light-colored material, reports theregister.co.uk