Earlier this year, researchers discovered that a vast liquid ocean lurks beneath the icy shell of Saturn's tiny moon ... no more than about 25 million years ago. "In other words, we think Mimas ...

A timelapse of all of the photographs the Cassini space probe has taken of Saturn's moon Mimas from Feb. 6, 2004 to Sept. 15, 2015. Note: These sequences at times include rapid flashing.