Feeds

Star-watchers: Famous moon left half-smeared by dirty ring

'Irregular grindings' responsible, apparently

Intelligent flash storage arrays

A well-known moon has been smeared half-dark by dirt coming from an enormous ring, according to reports.

Long-exposure shot of Iapetus, moon of Saturn, taken by the Cassini probe. Credit: NASA

The dirt boundary of Iapetus.

Science magazine has the story, quoting "ring specialist" Joseph Burns as saying: "It's nice to finally see a smoking gun that tells us exactly what happened."

Burns and his colleagues have long been interested in Iapetus, eighth moon of the famously ringy gas giant Saturn. Ever since it was discovered in the 17th century astronomers have been aware that the strange satellite had a bright face and a dark face, but have been unsure why this should be so.

The answer, it seems, is a previously unsuspected ring of dust, further out than the other rings of Saturn, which deposits an endless shower of dirt onto the leading face of Iapetus. As the moon is tidally locked - it doesn't spin about its own axis, instead always keeping the same face to its primary - all this dust settles on just one side.

Science reports that the new dirty ring's discovery was announced at an astronomers' conference in Puerto Rico yesterday. It seems that the new and record-breakingly large ring was detected by the Spitzer infrared space telescope orbiting the Earth.

The boffinry mag describes the process by which the doughnut-shaped dirt-cloud is continually replenished, even as much of it gets deposited on the grubby face of Iapetus:

At least three dozen or so "irregular" satellites, including Phoebe, whiz every which way within the giant ring. As wandering asteroids and comets hit these objects, they kick off debris, which in turn collide with other debris and strike yet more satellites. So the grinding down of irregular satellites produces the dust ring.

The dirty-ring moonsmear issue may not be confined to Iapetus, the scientists said. NASA boffins said that other moons both Saturnine and Jovian showed signs of similar darkening. ®

Top 5 reasons to deploy VMware with Tegile

More from The Register

next story
Rosetta probot drilling DENIED: Philae has its 'LEG in the AIR'
NOT best position for scientific fulfillment
LIFE, JIM? Comet probot lander found 'ORGANICS' on far-off iceball
That's it for God, then – if Comet 67P has got complex molecules
'Yes, yes... YES!' Philae lands on COMET 67P
Plucky probot aces landing on high-speed space rock - emotional scenes in Darmstadt
HUMAN DNA 'will be FOUND ON MOON' – rocking boffin Brian Cox
Crowdfund plan to stimulate Blighty's space programme
THERE it is! Philae comet lander FOUND in EXISTING Rosetta PICS
Crumb? Pixel? ALIEN? Better, it's a comet-catcher!
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
Post-pub nosh neckfiller: The MIGHTY Scotch egg
Off to the boozer? This delicacy might help mitigate the effects
I'M SO SORRY, sobs Rosetta Brit boffin in 'sexist' sexy shirt storm
'He is just being himself' says proud mum of larger-than-life physicist
NASA launches new climate model at SC14
75 days of supercomputing later ...
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security and trust: The backbone of doing business over the internet
Explores the current state of website security and the contributions Symantec is making to help organizations protect critical data and build trust with customers.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.