Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cassini finds more rings highlighted by telltale small particles

13.10.2006
Images taken by NASA's Cassini spacecraft, looking in the direction of the Sun, have provided scientists fresh insights into the dynamic nature of the rings and, in particular, the creation of new rings made from tiny particles released from larger bodies.

Cassini findings being presented this week at the Division for Planetary Sciences Meeting of the American Astronomical Society held in Pasadena, Calif. include several new faint ring structures formed by processes acting on and within Saturn's moons and main rings.

A series of unique observations gathered in mid-September by NASA's Saturn-orbiting Cassini spacecraft as it drifted slowly through Saturn's shadow, allowed the entire ring system to be seen from a perspective that highlights microscopic ring particles: in many cases, particles only recently released into Saturn orbit. While observing from this locale, Cassini spotted, a single faint new ring, announced previously, in the shared orbit of the moons Janus and Epimetheus.

Scientists are now ecstatic to find even more rings. A second new diffuse but narrow ring is coincident with the orbit of the tiny moon Pallene, also discovered by Cassini's imaging cameras and only 4 kilometers (2.5 miles) across. Curiously, another similar-sized moon called Methone, discovered earlier in the mission in roughly the same region, does not seem to sport a ring.

A third diffuse ring--the brightest seen in the Cassini Division between the main A and B rings--was also spotted on Sept. 15 from Saturn's shadow.

Finally, a faint, very narrow, and seemingly discontinuous ringlet was also found between the broad bands of ring material in the Cassini Division. Though too small to be resolved during the September observations, it too was first seen in images taken in a geometry that enhances the visibility of small particles.

"Cassini's superior cameras and close orbits around Saturn allow us to spot fainter and narrower rings than Voyager was able to see", said Dr. Joseph Spitale, an imaging team associate working with team leader Dr. Carolyn Porco. "I wouldn't be surprised if we find more as time goes on."

All of these new rings are likely formed and maintained by impacts onto larger bodies, whether moons or large ring particles. These impacts blast material off their surfaces, creating diffuse rings in the same orbit as the parent body.

Saturn's diffuse rings are a subset that includes the E, G, and newly discovered rings. Scientists suspect that the G ring is created by impacts into bodies trapped in a remarkably bright arc in the ring. Unlike the other diffuse rings, however, Cassini observations have confirmed that the E ring is created by tiny ice particles spewing from surface jets on the geologically active moon Enceladus.

No matter how they are released, small grains are pushed about by sunlight and by electrical forces; hence their distribution tells much about the local space environment.

Imaging scientists have also noticed color variations across the diffuse rings that imply active processes sort the particles along the ring according to their sizes. Looking at the faint rings on one side of Saturn, the E ring appears to have a red core with a bluish halo, but the appearance is reversed on the right side--where there is a blue ring interior to a red ring.

According to Dr. Matt Hedman, an imaging team associate working at Cornell University in Ithaca, NY, this color variation may imply particles are being sorted by some process according to their sizes.

"These tiny grains are like spices--even a little bit of material can alter the ring's character," Hedman said.

Additionally, Cassini acquired a movie sequence and other images showing the narrowly confined G ring and its faint arc of material, which is likely held in place by a gravitational resonance with one of Saturn's moons.

Imaging Team member Joe Burns, also of Cornell University remarks, "We've been stunned by the rings' variability. Who would have thought, even a few years ago, that we'd see so many new features as the Cassini mission progressed?"

Preston Dyches | EurekAlert!
Further information:
http://www.ciclops.org

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>