Feeds

Second PAC-MAN orbiting SATURN: Local absence of dots explained

'Could be a whole arcade out there,' says NASA boffin

The Power of One Infographic

NASA's Cassini mission has discovered a second Pac-Man moon in the Saturn system: Tethys.

Pac-Man moons in the Saturn system

Cassini already spotted the Pac-Man thermal shape on the Mimas moon in 2010, and this second shape - found in Tethys, one of Saturn's 62 icy moons - shows that warmer areas in this pattern could be pretty normal for moons.

"Finding a second Pac-Man in the Saturn system tells us that the processes creating these Pac-Men are more widespread than previously thought," said Carly Howett, lead author of a paper on Tethys.

"The Saturn system - and even the Jupiter system - could turn out to be a veritable arcade of these characters."

In the Pac-Man shape, the coldest part of the moon is in the mouth shape, while the surrounds reach a warmer temperature.

Boffins theorise that this happens when high-energy electrons bombard the low latitudes of the moon on the side that faces forward as it orbits, in this case around Saturn. That bombardment turns a small area of the moon into hard-packed ice, which can't heat as rapidly in the sunshine or cool down as quickly at night.

Finding the shape on Tethys proves that the electrons can dramatically alter the surface of an icy moon, even one that's also being hit with icy particles from Saturn's sixth-largest moon, Enceladus.

"Finding a new Pac-Man demonstrates the diversity of processes at work in the Saturn system," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory. "Future Cassini observations may reveal other new phenomena that will surprise us and help us better understand the evolution of moons in the Saturn system and beyond."

Astroboffins spotted the Pac-Man on Tethys in data from September 2011, where daytime temperatures in the mouth were cooler by 29 degrees Fahrenheit. At Tethys, unlike Mimas, the pattern can be seen very subtly in visible-light images as well as infrared, where it shows up as a dark region. ®

Eight steps to building an HP BladeSystem

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
MARS NEEDS OCEANS to support life - and so do exoplanets
Just being in the Goldilocks zone doesn't mean there'll be anyone to eat the porridge
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.