By Ron Cowen
Editor’s Note: A paper in the July 23 Nature reports on evidence for ammonia in the plume of water vapor and ice emanating from Saturn’s moon Enceladus, along with the probable detection of argon-40, raising the chances that Enceladus has (or had in the recent past) liquid water in its interior. Science News reported that finding in this story, originally posted in May.
Swooping within 25 kilometers of Enceladus, the Cassini spacecraft has obtained additional evidence that the interior of this tiny, icy moon of Saturn may contain liquid water. 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.