This color-enhanced image shows Enceladus, one of the moons of Saturn. It is one of the most reflective bodies in the solar system, with an almost pure white surface. Geysers of water and ice erupt from cracks near the moon's south pole (at top in this image from the Cassini spacecraft). The water comes from a global ocean beneath the moon's icy crust. The ocean may be warmed by mineral-rich thermal vents on the bottom, providing all the key ingredients for life: water, energy, and the right chemistry. [NASA/JPL]