Transcript: Enceladus is a modest but important moon of Saturn. Smaller than Titan, Rhea, Iapetus, and Tethys, it is only 500 kilometers in diameter. It has an unusual combination of old crater terrain and smooth icy planes. This moon forms a link between the old cratered surfaces on a moon like Ganymede and the smooth icy surfaces on a moon like Europa. Tidal heating has apparently caused watery eruptions that have resurfaced half of the surface of Enceladus. The icy regions of Enceladus are extremely reflective of light, reflecting 90 percent of the incident light. These bright regions of Enceladus are as white as a field of snow.