A recent analysis of images from NASA's Cassini spacecraft provides conclusive evidence that the jets of fine, icy particles spraying from Saturn's moon Enceladus originate from the hottest spots on the moon's "tiger stripe" fractures that straddle the moon's south polar region. Members of Cassini's imaging team used two years' worth of pictures of the geologically active moon to locate the sources of the most prominent jets spouting from the moon's surface

The possibility, first suggested by the imaging team, that the jets may erupt from pockets of liquid water, together with the unusually warm temperatures and the organic material detected by Cassini in the vapor accompanying the icy particles, immediately shoved this small Saturnian moon into the spotlight as a potential solar system habitable zone.

http://www.saturndaily.com/reports/Cassini_Pinpoints_Hot_Sources_Of_Jets_On_Enceladus_999.html