Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hot spot on Enceladus causes plumes

19.12.2007
Enceladus, the tiny satellite of Saturn, is colder than ice, but data gathered by the Cassini-Huygens Mission to Saturn and Titan has detected a hot spot that could mean there is life in the old moon after all. In fact, for researchers of the outer planets, Enceladus is so intellectually hot, it's smokin'.

The heat being generated on the moon's south pole at a hot spot is enough to eject plumes of ice and vapor above Enceladus. These plumes, according to William B. McKinnon, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, are this moon's most intriguing feature.

"The plume particles are like smoke, ice smoke," McKinnon said. "If you were standing on Enceladus' surface you wouldn't even be able to see the plumes. The particles are just larger than the wavelength of light, about one-thousandths of a millimeter. Most icy bodies of this size are geologically inert, but this is a clear indication of geological activity. Cassini has found active venting of water vapor. This leads to scientifically intriguing speculations and questions."

One is: Is this active ice volcanism on Enceladus? If so, is it due to ice sublimating, in the manner of a comet, or to a different mechanism, like boiling water, as in Old Faithful at Yellowstone?

The biggest question: If there is water on Enceladus, is there life?

"I don't think so," McKinnon said. "The strongest piece of evidence against that is measurements made from Earth of the plume don't show any sodium. If the source of the plumes were fresh water like on Earth, the plumes would contain enough detectable sodium. Fresh water flows through rocks and on streambeds, and so it picks up bits of mineral chemistry. The emerging view is that there's not obvious evidence for a subterranean ocean in contact with rock, no boiling or venting."

McKinnon said that the leading model for the cause of the plumes on Enceladus is that the moon's tides cause its crust to ratchet or rub back and forth in a set of faults near the south pole. This action generates just enough heat to vaporize the ice that makes the plumes.

Cassini, which has been passing through the plumes of Enceladus, makes its next pass in March of 2008. It will go deeper into the plume and take more pictures of the moon's features, the venting area in the infrared, impact craters, cracks and fissures, and make better measurements of gases and vapors.

McKinnon presented "Cold Fire: The Geology and Geophysics of Enceladus," Dec. 10, 2007, at the Fall Meeting of the American Geophysical Union in San Francisco.

The mythological Enceladus is buried beneath Mount Etna and is responsible for the mountain's tremors and volcanism. The moon Enceladus is only 500 kilometers wide — roughly 300 miles wide, the distance between St. Louis and Chicago, and quite round for such a small body. Data from Cassini has revealed a rock-rich body, 55 to 60 percent rock by mass, with a surface of nearly pure water ice.

The temperature at the poles is some -220 degrees Celsius (C), but the hot spot is at least 100 degrees warmer. Enceladus is in a special relationship called dynamical resonance with another one of Saturn's moons, Dione. Every time Dione, in an exterior orbit around Saturn, circles Saturn, Enceladus goes around exactly twice. This resonance keeps Enceladus' orbit tidally pumped, maintaining an eccentric path that leads to a continuous squeezing under Saturn's gravity field.

This process makes a small part of the planet hot, relatively, for an icy satellite. It's the same mechanism that runs the tremendously hot silicate volcanism of Io and activates Europa, maintaining its ocean. Io and Europa are two of Jupiter's moons.

"You only have to get so hot to make ice active," McKinnon said. "It doesn't have to get tremendously hot like it does on Io. Ice volcanism requires an order of magnitude less energy for things to work out pretty well. The hot spots are -100 degrees C or possibly 'warmer'; the area around it is more than twice as cold. We still can't say how truly 'hot' the hot spots are. We'll probably learn this in March."

Tony Fitzpatrick | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Physics and Astronomy:

nachricht MEMS chips get metatlenses
21.02.2018 | American Institute of Physics

nachricht International team publishes roadmap to enhance radioresistance for space colonization
21.02.2018 | Biogerontology Research Foundation

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: 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...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

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

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>