Waka waka waka? Pac-Man: The Sequel

At one point it was just Mimas, one of Saturn’s 62 moons, that looked like 80’s gaming legend Pac-Man. Now Tethys, another Saturnian natural satellite, becomes the second.

The unusual pattern, recorded using NASA’s Cassini probe’s thermal imager, was first spotted on Mimas in 2010, with the warmer areas making up the Pac-Man shape. Recent observations, published in the journal ICARUS, reveal Tethys to possess a similar anomalous heat pattern.

It has been theorized that the unusual pattern of both moons is formed due to the impact of high-energy electrons generated from Saturn’s magnetosphere. Both moons are composed of water-ice, with Saturn-facing struck areas at lower latitudes converted to hard-packed ice, increasing its thermal conductivity. This causes the affected regions to heat more slowly during the day and cool more slowly at night, generating the anomalous heat patterns. Electron bombardment patterns match up with the unexpected heat maps.

Mimas already has another claim to fame — from certain angles, it looks like the Star Wars Death Star (above). The image is created due to Mimas’ huge impact crater, Herschel, named after the moon’s discoverer. The Herschel crater, almost a third of the diameter of Mimas and wider than Australia, also resembles one of the power pellets from the original Pac-Man.

DOI: 10.1016/j.icarus.2012.10.013