Evidence for Enceladus’ liquid interior

Hunter Waite of the Southwest Research Institute in San Antonio and his colleagues base their findings on close-up observations made with Cassini’s Ion and Neutral Mass Spectrometer, which on March 12, 2008 and October 9, 2008 tasted the plumes of icy particles and water vapor known to spew from the moon.

In a research abstract for a talk at the 2009 Joint Assembly of the American Geophysical Union in Toronto, Waite and his collaborators cite two findings that they say “provide compelling evidence for the existence—today or in the recent past—of liquid water in Enceladus’ interior.”

Last year Waite spoke about the preliminary results of the March 12 flyby. It was “a completely unexpected surprise [that the chemistry of Enceladus interior] resembles that of a comet,” said Waite. “To have primordial material coming out from inside a Saturn moon raises many questions on the formation of the Saturn system.”

“Enceladus is by no means a comet,” he added. “Comets have tails and orbit the sun, and Enceladus’ activity is powered by internal heat while comet activity is powered by sunlight. Enceladus’ brew is like carbonated water with an essence of natural gas.”