Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New CU-Boulder study detects first known belt of moonlets in Saturn's rings

26.10.2007
Unseen moonlets range in size from moving vans to domed sports arenas

A narrow belt harboring moonlets as large as football stadiums discovered in Saturn's outermost ring probably resulted when a larger moon was shattered by a wayward asteroid or comet eons ago, according to a University of Colorado at Boulder study.

Images taken by a camera onboard the NASA Cassini spacecraft revealed a series of eight propeller-shaped "wakes" in a thin belt of the outermost "A" ring, indicating the presence of corresponding moonlets, said CU-Boulder Research Associate Miodrag Sremcevic, lead author of the study published in the Oct. 25 issue of Nature. The propeller wakes highlight tiny areas of the belt where ring material has been perturbed by the gravitational forces caused by individual moonlets, Sremcevic said.

The team calculated that there likely are thousands of moonlets ranging in size from semi-trailers to sports arenas embedded in the "A" ring's thin moonlet belt that circles the planet. At about 2,000 miles across, the belt of moonlets is only about 1/80th the diameter of Saturn's total ring system, which at roughly 155,000 miles across would stretch about two-thirds of the way from Earth to the moon.

"This is the first evidence of a moonlet belt in any of Saturn's rings," said 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."

Co-authors of the Nature study include Juergen Schmidt, Martin Seiss and Frank Spahn of the University of Potsdam in Germany, Heikko Salo of the University of Oulu in Finland, and Nicole Albers of CU-Boulder's LASP. The images were taken by the Narrow Angle Camera onboard the NASA Cassini spacecraft, which was launched in 1997 and has been orbiting the Saturn system since July 2004.

Each propeller feature is about 10 miles long, said Sremcevic, who with Spahn first predicted the existence of such propellers in Saturn's rings as an undergraduate at the University of Belgrade in 2000. While four propellers were discovered in the "A" ring in 2006 by a team led by Cornell University, Sremcevic and his colleagues looked at a much larger image sequence, allowing them to extrapolate statistically and confirm the presence of thousands of small objects in the "A" ring's moonlet belt.

The moonlets may be the result of the break-up of a ring-moon similar to Pan -- Saturn's innermost 20-mile diameter moon -- that was smashed by a comet or meteor, the team concluded. The team calculated the mass of the unseen moonlets in the belt greater than 50 feet in diameter to arrive at the estimated size of the moon involved in the collision creating the belt.

The finding supports the theory that Saturn's rings initially were created in a "collisional cascade" of ring debris begun by a catastrophic break-up of an even larger moon in the Saturn system first proposed by CU-Boulder planetary scientists Larry Esposito and Joshua Colwell in 1987. The moonlets in the newly discovered belt may have formed after Saturn's rings already were in place, which planetary scientists speculate could have been hundreds of millions or even billions of years ago.

"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," the researchers wrote in Nature. "Instead, the moonlet belt is compatible with a more recent body orbiting in the A ring."

Esposito, who was not involved in the study, said the propellers "show a striking demonstration of the lingering effects of the gravity from these small, embedded moonlets." Esposito is the chief scientist on the NASA Cassini mission's $12.5 million Ultra-Violet Imaging Spectrograph designed and built at LASP.

Sremcevic said the discovery of the moonlet belt is another piece in the puzzle regarding the formation and evolution of Saturn's rings. "We believe future studies of ring evolution will need to incorporate the findings and implications from this study."

Miodrag Sremcevic | EurekAlert!
Further information:
http://saturn.jpl.nasa.gov
http://www.colorado.edu/news/podcasts/

More articles from Physics and Astronomy:

nachricht Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>