Cassini snaps icy moon Dione

Like a wrinkled dowager, Saturn’s small moon Dione has a heavily cratered and fractured surface. The first close-up portrait of this moon, recorded by the Cassini spacecraft on Oct. 11 when it passed within

500 kilometers, shows that Dione’s surface bears the scars of multiple generations of fractures that haven’t been erased by any relatively recent upheavals.

That’s in marked contrast to Saturn’s more youthful moon Enceladus, which lies nearby in the planet’s E ring and was probed earlier this year by Cassini. Some of the most striking fractures on Enceladus may be only a decade old, testimony to large-scale geologic motions.

“Enceladus is the up-and-coming moon, complete with a recently active history, while Dione is the older, more mature moon,” says Bonnie Buratti of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.