Feeds

Cassini team spies moonlets in Saturn's A ring

You can tell by the propellers

Next gen security for virtualised datacentres

Many years ago, a comet strike or a wandering asteroid passing through Saturn's moon system, crashed into one of the orbiting bodies, shattering it and sending fragments the size of sports stadia whirling along its orbital path.

Moonlets orbiting Saturn. Credit: NASA

Moonlets orbiting Saturn. Credit: NASA

New images from NASA's Cassini spacecraft have identified a series of "propellor-like" features that researchers think are the result of such a collision. The Cassini imaging team, including experts from the University of Boulder, Colorado, interprets the propellers as being the wake caused by small moonlets.

These bodies are too small to clear out surrounding ring material, but can still attract smaller particles to form the propeller shape. The largest of those in the image (in the white edged box out) is said to be roughly 150 metres wide. The size is inferred from the separation of the propeller wings.

The first such features were seen in 2004, but the latest pictures have revealed that the moonlets are grouped together in a 3,000km wide belt of material.

"This is the first evidence of a moonlet belt in any of Saturn's rings," said Miodrag Sremcevic of CU-Boulder's Laboratory for atmospheric and space physics. "We have firmly established these moonlets exist in a relatively narrow region of the 'A' ring, and the evidence indicates they are remnants of a larger moon that was shattered by a meteoroid or comet."

The team calculates that the region may hold many thousands of these moonlets, ranging in size from a small truck to that of a sports stadium. Each propeller feature is about 16km long, the result of gravitational disturbances of the dusty ring.

The researchers say the findings support the idea that Saturn's rings were all created during a "collisional cascade" of ring debris, prompted by the breakup of a much larger moon. But the moonlets belt probably came later, after the ring system was well established (scientists think Saturn's rings have been there for hundreds of millions, possibly even billions of years).

In the paper, published in Nature, the team writes: "It seems unlikely that moonlets are remainders of a single catastrophic event that created the whole ring system, because in this case a uniform distribution would emerge. Instead, the moonlet belt is compatible with a more recent body orbiting in the A ring."

You can view a larger version of the image here. ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
LOHAN tunes into ultra long range radio
And verily, Vultures shall speak status unto distant receivers
EOS, Lockheed to track space junk from Oz
WA facility gets laser-eyes out of the fog
Volcanic eruption in Iceland triggers CODE RED aviation warning
Lava-spitting Bárðarbunga prompts action from Met Office
NASA to reformat Opportunity rover's memory from 125 million miles away
Interplanetary admins will back up data and get to work
LOHAN Kickstarter breaks NINETEEN THOUSAND of your EARTH POUNDS
That's right, OVER 9,000 beer tokens - and counting
Major cyber attack hits Norwegian oil industry
Statoil, the gas giant behind the Scandie social miracle, targeted
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Advanced data protection for your virtualized environments
Find a natural fit for optimizing protection for the often resource-constrained data protection process found in virtual environments.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.