Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cassini finds recent, unusual geology on Enceladus

27.07.2005


New detailed images taken by NASA’s Cassini spacecraft of the south polar region of Saturn’s moon Enceladus reveal distinctive geological features, and the most youthful terrains of any seen on Enceladus. These findings point to a very complex evolutionary history for Saturn’s brightest, whitest world.



Cassini’s flyby on July 14 brought it within 175 kilometers (109 miles) of the surface of the icy moon. The close encounter revealed a landscape near the south pole littered with house-sized ice boulders, carved by tectonic patterns unique to Enceladus, and almost entirely free of impact craters. These features set the southerly region apart from the rest of the moon.

The new image products can be seen at http://ciclops.org, http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini.


As white as fresh snow, Enceladus (505 kilometers, 314 miles across) has the most reflective surface in the solar system. Previous Cassini flybys have revealed that Enceladus, in contrast to the other icy moons of Saturn, possesses lightly cratered regions, fractured plains and wrinkled terrain.

The new findings add to the story of a body that has undergone multiple episodes of geologic activity spanning a considerable fraction of its lifetime, and whose southern-most latitudes have likely seen the most recent activity of all. These same latitudes may also bear the scars of a shift in the moon’s rate of spin. This speculation which, if true, may help scientists understand why Enceladus has a tortured looking surface, with pervasive crisscrossing faults, folds and ridges.

The most remarkable images show ice blocks, about 10 to 100 meters (33 to 328 feet) across, lying in a region that is unusual in its lack of the very fine-grained frost that seems to cover the rest of Enceladus.

"A landscape littered with building-sized blocks was not expected," said Dr. Peter Thomas, an imaging team member from Cornell University, Ithaca, N.Y. "The minimal cover of finer material and the preservation of small, crossing fracture patterns in the surrounding areas indicate that this region is young compared to the rest of Enceladus."

False color composites of this region, created from the most recent images, show the largest exposures of coarse-grained ice fractures seen anywhere on the satellite. It also supports the notion of a young surface at southern latitudes.

"These southern exposures of coarse-grained ice are aligned with tectonic "stripes" and not covered by the fine-grained materials that one would expect from various space weathering processes," said Dr. Alfred McEwen, an Imaging Team member at the University of Arizona, Tucson.

The apparent absence of sizable impact craters also suggests that the south pole is younger than other terrains on Enceladus. These indications of youth are of great interest to scientists who have long suspected Enceladus as one possible source of material for Saturn’s extensive and diffuse E ring, which coincides with the icy moon’s orbit. Young surfaces represent a challenge as it has generally been believed that Enceladus is too small and too cold to generate the heat required to modify its surface.

Some of the latest images, which have revealed additional examples of a distinctive "Y-shaped" tectonic feature on Enceladus in which parallel ridges and valleys appear to systematically fold and deform around the south polar terrains, may hint at the answer.

"These tectonic features define a boundary that isolates the young, south polar terrains from older terrains on Enceladus," noted Dr. Paul Helfenstein, an associate of the Imaging Team also at Cornell University. "Their placement and orientation may tell us a very interesting story about the way the rotation of Enceladus has evolved over time and what might have provided the energy to power the geologic activity that has wracked this moon."

Cassini will explore Enceladus further in a future close flyby planned for March 2008.

Preston Dyches | EurekAlert!
Further information:
http://www.nasa.gov

More articles from Physics and Astronomy:

nachricht Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>