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Out of This World


The PacMan-shaped hot spot has baffled scientists. Image: NASA/JPL

By David Reneke

Dave Reneke brings news from the space and astronomy communities around the world.

David Reneke is an astronomy educator, writer and broadcaster who represents Australasian Science on more than 60 networked radio stations across Australia. He also produces a range of educational CD-ROMS on astronomy and space exploration for beginners, and runs an astronomy outreach program for schools throughout NSW. Subscribe to David’s free Astro-Space newsletter at

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PacMan in the Moon
Were you a closet PacMan player? If the image here looks familiar then you’re going to like this story.

The highest resolution temperature map ever taken of Mimas, one of Saturn's small inner moons, has revealed a surprising pattern on the rocky surface – a PacMan-shaped hot area that scientists are now trying to explain.

Not only did the fly-by of Mimas by NASA’s Cassini spacecraft on 13 February reveal the yellowish computer game shape, it also highlighted the vast Herschel crater that looks like the Death Star from Star Wars. It also revealed a bizarre pattern of unexplained daytime temperatures across this enigmatic 600 km-wide world.

"Other moons usually grab the spotlight, but it turns out Mimas is more bizarre than we thought it was," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena. "It has certainly given us some new puzzles."

One of the biggest questions researchers are asking is what is causing the sudden temperature change on either side of the two straight lines that form PacMan's “mouth”. The warmest region was in the morning, along one edge of the moon's disc, making a sharply defined PacMan shape, with temperatures around –294°F.

The rest of the moon was almost 30° colder. A smaller warm spot, the dot in PacMan's mouth, showed up...

The full text of this article can be purchased from Informit.