May 29, 2013 11:57 PM EDT
Hints of Activity on Saturn Moon Dione
From a distance, most of the Saturnian moon Dione resembles a bland cue ball. Thanks to close-up images of a 500-mile-long (800-kilometer-long) mountain on the moon from NASA's Cassini spacecraft, scientists have found more evidence for the idea that Dione was likely active in the past. It could sti...