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 Basque researchers turn light upside down
23.02.2018 | Elhuyar Fundazioa

nachricht Attoseconds break into atomic interior
23.02.2018 | Max-Planck-Institut für Quantenoptik

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: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>