Feeds

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

'Irregular grindings' responsible, apparently

Top 5 reasons to deploy VMware with Tegile

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
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
Antarctic ice THICKER than first feared – penguin-bot boffins
Robo-sub scans freezing waters, rocks warming models
Your PHONE is slowly KILLING YOU
Doctors find new Digitillnesses - 'text neck' and 'telepressure'
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
The next big thing in medical science: POO TRANSPLANTS
Your brother's gonna die, kid, unless we can give him your, well ...
NASA launches new climate model at SC14
75 days of supercomputing later ...
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
prev story

Whitepapers

Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Designing and building an open ITOA architecture
Learn about a new IT data taxonomy defined by the four data sources of IT visibility: wire, machine, agent, and synthetic data sets.
How to determine if cloud backup is right for your servers
Two key factors, technical feasibility and TCO economics, that backup and IT operations managers should consider when assessing cloud backup.
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.