Cassini recently took this image of Saturn's icy moon Enceladus above the planet's sweeping rings. Although the rings are made largely of ice, they've become dirty because of contamination from meteoritic dust gathered over hundreds of millions of years. Enceladus, on the other hand, looks comparatively pristine. There must be some process that continues to resurface Enceladus, to keep it from turning the same dusty colour.