Saturn’s Moon Mimas Looks Like Pac-Man In Infrared
In an earlier article we have showed you how Saturn’s moon Mimas totally looks like the Death Star from the Star Wars movies. Now it seems that Mimas also looks like Pac-Man from the 1980s video game when seen in infrared.
How the Picture Was Taken
The picture above has been taken by the composite infrared spectrometer (CIRS) from the Cassini spacecraft, which is the result of the cooperation between NASA and ESA (the European Space Agency).
The unusual Pac-Man shaped thermal pattern was first identified in 2010 during a close flyby of Mimas by the Cassini spacecraft.
Why the Heat Map Looks Unusual
As the graphic below explains, normally the temperature distribution on any planet, moon or smaller body should be distributed in circular patterns. The equatorial region facing the sun is usually the hottest. Also, the farther we get from that region, the colder it should get. However with Mimas the heat map is nothing like it should be! A Pac-Man shaped region of the moon shows a very different temperature behavior than the rest of the surface. Except for some minor heat spots corresponding to the Herschel crater (the one that makes Mimas look like the Death Star), the pattern is highly unusual.
The Role of Saturn’s Magnetosphere
Scientists now believe that this strange pattern is caused by high-energy electrons from Saturn’s magnetosphere striking the leading hemisphere of Mimas as it travels through space. These energetic particles alter the structure of the surface ice. They compact it and change how the surface absorbs and releases heat.
Surface Differences and Thermal Inertia
The difference in texture and albedo between the two hemispheres could explain some of the hotter regions. The compacted ice in the affected region gives it higher thermal inertia. This means it warms up more slowly during the day and stays warmer at night than surrounding areas. However the minor heat spots corresponding to the Herschel crater are a normal occurrence. Huge craters have been known to trap some heat inside.
Similar Patterns on Other Moons
Interestingly, scientists have observed a similar Pac-Man shaped thermal pattern on Saturn’s moon Tethys. This supports the idea that energetic particle bombardment from Saturn’s magnetosphere is responsible for the effect.
Would you like to receive similar articles by email?
Paul Tomaszewski
Paul Tomaszewski is a science & tech writer as well as a programmer and entrepreneur. He is the founder and editor-in-chief of CosmoBC. He has a degree in computer science from John Abbott College, a bachelor's degree in technology from the Memorial University of Newfoundland, and completed some business and economics classes at Concordia University in Montreal. While in college he was the vice-president of the Astronomy Club. In his spare time he is an amateur astronomer and enjoys reading or watching science-fiction. You can follow him on LinkedIn and Twitter.
One Comment
Daniel Amezcua
That is awesome! Now I feel like I need to go find my Atari.