The Cassini spacecraft’s composite infrared spectrometer (CIRS) has returned some space pictures that have geeks all over giggling due to a clear Pac Man sihouette.
Cassini snapped the images on February 13th of the Saturnian moon Mimas. The 396 km diameter moon is believed to be mostly water ice with some rock present, and NASA scientists commented on the unusual shape of the data:
NASA explains that scientists “expected smoothly varying temperatures peaking in the early afternoon near the equator”, but instead “the warmest region was in the morning, along one edge of the moon’s disk, making a sharply defined Pac-Man shape, with temperatures around 92 kelvin.”
Scientists believe that the results are due to differences in surface texture of ice and snow, not unlike when snow on the front lawn that’s old and crusty gets covered with new, powdery snow:
“Denser ice quickly conducts the heat of the sun away from the surface, keeping it cold during the day. Powdery ice is more insulating and traps the sun’s heat at the surface, so the surface warms up.”
NASA speculates on further possible causes for space Pac Man here, but scientists admit there’s no clear reason why Mimas looks like Pac Man in the first place:
(Cassini CIRS team member John) Spencer expressed doubts, however, and conceded it’s “hard to understand why this dense top layer would remain intact when meteorites and other space debris should have pulverized it by now”.
Because, John, Pac Man is awesome.