NASA shares close-up portrait of Saturn's moon Dione

March 13 (UPI) -- A newly shared NASA photo offers a closeup view of Saturn's moon Dione -- a small, simple satellite.

Dione stretches just 698 miles across, making it Saturn's 15th largest moon. Saturn hosts 62 known moons. Surprisingly, Dione is larger than all of its more diminutive peers combined.

Astronomers believe Dione's outer layers of water ice hide a dense core made of silicate rock. And because the satellite is so cold -- negative 304 degrees Fahrenheit on most days -- its ice layers behave like rock.

The photo, shared this week by NASA, was snapped by NASA's Cassini probe in 2012.

Last fall, Cassini executed a final dive into Saturn's atmosphere, ending its 13-year tour of the ringed planet.

NASA scientists hope to plan and execute a return scientific mission to Saturn in the coming decades, as many of Saturn's moons have been identified as promising targets in the search for alien life.