NASA Cassini Images: Saturn's moon Mimas with Pacman profile

NASA's Cassini spacecraft has made the most amazing discovery in the history of science: an image of Pac-Man on the Death Star.

This is the temperature map of Mimas, Saturn's icy moon. As you can see, it's basically a giant Pac-Man about to eat a power pellet. According to Cassini project scientist at NASA's Jet Propulsion Laboratory Linda Spilker, this is really weird:

Other moons usually grab the spotlight, but it turns out Mimas is more bizarre than we thought it was. It has certainly given us some new puzzles.

NASA scientists at NASA Goddard Space Flight Center have some ideas. According to Dr. Mike Flasar, composite infrared spectrometer principal investigator at Goddard, the culprit may be the giant Herschel crater:

Even though we can't explain the observed pattern of surface temperatures on Mimas, the giant Herschel crater is a leading suspect. The energy of impact that created it several billion years ago has been estimated to be one-seventh of Mimas's own gravitational energy.

Anything much larger would likely have torn the moon apart. We really would like to see if there is also an anomalous temperature pattern on the other side of Herschel, which has not been observed so closely.

Cornell University's Paul Helfenstein—who's an associate in the Cassini imagine team—speculates that the pattern may be related to "silicate minerals or carbon-rich particles, possibly because of meteor dust falling onto the moon or impurities already embedded in surface ice.

As the sun's warming rays and the vacuum of space evaporate the brighter ice, the darker material is concentrated and left behind. Gravity pulls the dark material down the crater walls, exposing fresh ice underneath."