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Illustration of a geyser erupting on the surface of Enceladus. Liquid water reaches the surface of Enceladus' south pole and drives a massive plume of ice crystals into the sky. The combination of Enceladus' low surface gravity and the geyser's force accelerate the crystals to escape velocity, where sunlight breaks the water molecules down into their constituent atoms of hydrogen and oxygen. Saturn itself appears low on the horizon due to the proximity to Enceladus' pole. The small object immediately to Saturn's left is another icy moon named Mimas. Somewhat smaller than Enceladus and closer to Saturn, Mimas sprints around Saturn in slightly less than one Earth day. In March 2006 NASA's Cassini probe revealed evidence of water09/14/2009driven geysers on the surface of Enceladus. At first glance Enceladus doesn't seem to be a likely host for liquid water as the surface is extremely cold, about 09/14/2009330 F. However, tidal forces from Saturn's massive gravity alternately pull and push on Enceladus' interior, creating enough heat to melt the water ice immediately beneath the surface. This heated water is believed to periodically erupt like a volcano, a process known as cryovolcanism.