Water Found on Saturn’s Moon

| | Vapor plumes on Enceladus, Courtesy Ciclops.org|

The Cassini spacecraft has found evidence of geysers on Enceladus, a strange, cold moon of Saturn. This discovery brings the total number of places in the known universe with liquid water to two: there and Earth. (Mars had liquid water long ago, and Jupiter's moon Europa is only suspected of having a liquid ocean buried under ice.) Carolyn Porco, the always-enthusiastic Cassini imaging team leader, describes the findings thusly in her e-mail announcement:

_ What we have discovered about the story of Enceladus is thrilling beyond imagination: more heat emerging from the south polar region, per square meter, than from the Earth and, possibly, subterranean organic-rich bodies of liquid water only tens of meters beneath the south polar terrain. If we did nothing else, these findings alone would have made the Cassini mission worthwhile._

We've written about Cassini twice in recent years: a preview of the mission as it arrived in July 2004 and an update on its incredible findings in April 2005. Perhaps it's time for another look. —Michael Moyer