Wednesday, March 9, 2011

Cassini Finds Enceladus is a Powerhouse

PASADENA, Calif. -- Heat output from the south polar region of Saturn's moon Enceladus is much greater than was previously thought possible, according to a new analysis of data collected by NASA's Cassini spacecraft. The study was published in the Journal of Geophysical Research on March 4.

Data from Cassini's composite infrared spectrometer of Enceladus' south polar terrain, which is marked by linear fissures, indicate that the internal heat-generated power is about 15.8 gigawatts, approximately 2.6 times the power output of all the hot springs in the Yellowstone region, or comparable to 20 coal-fueled power stations. This is more than an order of magnitude higher than scientists had predicted, according to Carly Howett, the lead author of study, who is a postdoctoral researcher at Southwest Research Institute in Boulder, Colo., and a composite infrared spectrometer science team member.

"The mechanism capable of producing the much higher observed internal power remains a mystery and challenges the currently proposed models of long-term heat production," said Howett.

It has been known since 2005 that Enceladus' south polar terrain is geologically active and the activity is centered on four roughly parallel linear trenches, 130 kilometers (80 miles) long and about 2 kilometers (1 mile) wide, informally known as the "tiger stripes." Cassini also found that these fissures eject great plumes of ice particles and water vapor continually into space. These trenches have elevated temperatures due to heat leaking out of Enceladus' interior.

A 2007 study predicted the internal heat of Enceladus, if principally generated by tidal forces arising from the orbital resonance between Enceladus and another moon, Dione, could be no greater than 1.1 gigawatts averaged over the long term. Heating from natural radioactivity inside Enceladus would add another 0.3 gigawatts.

The latest analysis, which also involved the composite infrared spectrometer team members John Spencer at Southwest Research Institute, and John Pearl and Marcia Segura at NASA's Goddard Space Flight Center in Greenbelt, Md., uses observations taken in 2008, which cover the entire south polar terrain. They constrained Enceladus' surface temperatures to determine the region's surprisingly high output.

A possible explanation of the high heat flow observed is that Enceladus' orbital relationship to Saturn and Dione changes with time, allowing periods of more intensive tidal heating, separated by more quiescent periods. This means Cassini might be lucky enough to be seeing Enceladus when it's unusually active.

The new, higher heat flow determination makes it even more likely that liquid water exists below Enceladus' surface, Howett noted.

Recently, scientists studying ice particles ejected from the plumes discovered that some of the particles are salt-rich, and are probably frozen droplets from a saltwater ocean in contact with Enceladus' mineral-rich rocky core. The presence of a subsurface ocean, or perhaps a south polar sea between the moon's outer ice shell and its rocky interior would increase the efficiency of the tidal heating by allowing greater tidal distortions of the ice shell.

"The possibility of liquid water, a tidal energy source and the observation of organic (carbon-rich) chemicals in the plume of Enceladus make the satellite a site of strong astrobiological interest," Howett said.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The CIRS team is based at NASA's Goddard Space Flight Center in Greenbelt, Md., where the instrument was built.

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13 comments:

  1. Flooding in Northeast and Atlantic Seaboard based on spring melt of record snowfalls, and now, torrential rainfall predicted for the entire area today as well. Could be that the eastern US is headed toward a record spring of flooding a la eastern Australia. Of course we know what the authoritarians' take on this will be already: This proves that global warming is a hoax! We've got global cooling if we've got anything at all!

    Sigh...

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  2. The U.S. will not lead in any serious attempts at serious space travel in the future if our educational system is any indication.

    Some eighty-two percent (82%) are said to be failing under some indicators.

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  3. Do you think that this fellow is an example of what could be the nucleus of the Next Civilization.

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  4. Serious space travel will soon seem like the pie in the sky dream it always was. As the petroleum age continues to wane, our attentions will turn to more pressing concerns, such as dealing with mass starvation and impoverishment, and what prophets have long called "the war of all against all."

    The holy terror we will have unleashed by squandering a few millions years of concentrated solar energy in just 200 years give or take will be like nothing humanity has ever experienced. With 7 billion people and counting and MOMCOM supplied weapons in the hands of just about everyone who wants them, the end of this civilization is guaranteed to be the pyrotechnic show of the millennium.

    And as the prime perpetrator of all these crimes against humanity, we here in the US will eventually have a well earned and fully deserving front row seat right in the middle of it. Seeing as we're still accelerating full-bore into the teeth of this perfect storm, it won't be long now either. Not long at all.

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  5. disaffected,

    "space travel ... the pie in the sky dream it always was ..."

    That is tantamount to saying continued human existence is a pie in the sky dream.

    A TOP doctor (Toxins of power) might say, the toxins of power epidemic wiped them out.

    But cosmic health, as an abstract hypothesis, is not pie in the sky in terms of "can it be done?" ...

    However, on this planet the powers that be, infected with the toxins of power that be, have chosen dementia over wisdom.

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  6. disaffected,

    "nothing humanity has ever experienced"

    The story of the guy I linked to at my 6:30 PM comment may be a story about the future citizen of The Next Civilization.

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  7. Dredd,

    The desert guy's certainly kitcschy, but long term viable his lifestyle is not. When the petrol and the technology that goes with it (including most notably, easy access to water in a desert) is gone, so will be masses (or even small enclaves for that matter) of humans living in inhospitable environments.

    Left to our natural devices, most of the western and central US is unlivable (and will certainly be unbearably uncomfortable long before that), and when petrol enabled farming practices and transportation goes by the wayside, there will go the cheap food supplies for the remaining hordes that congregate in the Pacific Northwest or the Eastern Seaboard. The resulting culling of the herd promises to be a "fun ride" of epic proportions.

    The American Indians had the whole sustainable and environmentally conscious culture thing down pat 150 years ago, for which we slaughtered them and confined the rest to reservations. Don't look now, but the tables are going to be turned in our lifetimes, and the demise of the European white man's culture - which has since infected the entire world! - is going to make the slaughter of the Indian culture look like a mere garden party. Call it cosmic justice.

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  8. disaffected,

    "The desert guy's certainly kitcschy"

    Actually the civilization that will generate many of these people, those fortunate to survive, is what should be defined as "kitcschy" ("is a form of art that is considered an inferior, tasteless copy of an extant style of art or a worthless imitation of art of recognized value. The concept is associated with the deliberate use of elements that may be thought of as cultural icons while making cheap mass-produced objects that are unoriginal" - Wikipedia).

    Kitsch is so MOMCOM.

    Cheap, plastic, fake, polluting art is the clothing of MOMCOM, from Twinkies to "MOMCOM freedom" and "MOMCOM peace".

    MOMCOMism is a regular riot that will destroy most everything ... except a few people living in a desert that will probably be named "MOMCOM was here" ...

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  9. Actually the civilization that will generate many of these people, those fortunate to survive, is what should be defined as "kitcschy"

    I agree totally. It's just that the idea perpetuated by guys like this that there will be some orderly, back to basics, extended power-down of western culture is totally misleading and false. He's had years and all the advantages of current technology and culture to set up his little abode in the west Texas desert. Absent outside help, he wouldn't last 6 months out there, and even if he did, the existence itself would be stultifying.

    On the other hand, the Times' photos were absolutely awesome.

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  10. "there will be some orderly, back to basics, extended power-down of western culture is totally misleading and false"

    I don't think those are the sentiments of that fellow.

    You are talking about the reaction to events after they have happened, but the focus needs to be on what will happen and how to prepare for it.

    The sentiments of a commune in Tennessee is also instructive as to vision.

    That commune (the Farm) has been in the minds of some young folk since the mid-60's when some San Francisco hippies began to think about a better way of life, then eventually left in buses for a new home, a new direction, ending up in Tennessee of all places.

    They are still there having learned what it takes to live together when the grocery store and the gas station go away.

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  11. Now that (the farm) I can agree with, at least in principle. For the guy in west Texas, I think a better vision of what it would be like to live in such an environment after the age of petrol (and it still wouldn't be very accurate), would to take a journey a few hundred miles south into old Mexico and see how the peasant farmers manage to scratch out a living on such a landscape. Answer: POORLY and BARELY. Thanks to American narco-capitalism, most turn to cultivating marijuana, but absent that, they barely survive at all.

    The Texas fellow admitted right up front that his land search took him far and wide in search of a place where no evidence of human habitation could be seen around him, so I got the feeling that his enterprise was much more of a social experiment than anything else. Which is fine, for as far as it goes. However, the idea that more than a VERY SMALL handful of people would ever be able to pull such a thing off (or even want to) is outlandish to my mind.

    I envision such circumstances resulting in more of a turning back of the clock by leaps and bounds. Such as, the first jump might be to a 1940s-50s type existence, where things just drastically slow down and get a whole lot tougher. The next stop might be turn of the 20th century, as mass produced technologies fall by the wayside wholesale and everything starts reverting back to local. Followed shortly thereafter by mid 1800s, where everything's local, animal powered, cold, hot, and otherwise brutal. Might take us 100 years to get all the way there, but that's not all that long in the grand scheme of things. Shoot, it's only been 50 years since my grandparents in Nebraska first got indoor plumbing and heating (believe it or not!).

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  12. disaffected,

    That way-back-machine scenario is well and good, but as in your other post up thread, I agree that it will be even more difficult than the folks you referred to had it.

    For instance, bees around the world are going bye bye:

    "The way humanity manages or mismanages its nature-based assets, including pollinators, will in part define our collective future in the 21st century," said UNEP executive director Achim Steiner.

    "The fact is that of the 100 crop species that provide 90 percent of the world's food, over 70 are pollinated by bees," he added
    . (Breitbart)

    Add to that the heavy damage to the other parts of the environment, and the prospects are much more difficult than our people 200 years ago had it.

    I mean, the earth was much more healthy then.

    But the point is that those who are going through some training now will do better than those who are going into the dark ages on steroids unprepared.

    Survival of the fittest sometimes means survival of those who saw it coming and did sensible things to prepare.

    Good luck!

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  13. Dredd,

    I agree with all with all your comments, especially the particularly salient point that going back ain't going to be anywhere near as simple as simply rewinding the clock. We've done extensive damage to the eco system in the meantime that can't be undone.

    My only point really, in a nutshell, is that most of the "back to the future" types that I've seen seem to assume a level of technological sophistication going forward into the era of resource depletion that I doubt will be there. Solar panels are a great example. They're great for very low powered and simple tasks, and solar energy in general is great for things like warming (not heating) water and living areas on sunny days (which west Texas certainly has a lot of), but the technology that created and manufactured solar panels (and mined all the rare earth metals that go into creating them) and just about anything else of the current age, is all oil and coal fueled. As such, once the oil and the coal (and mining coal requires abundant supplies of oil too) are in short supply, all of those easily manufactured items will be gone.

    I simply think that most of the eco triumphalists - for all the other VERY REAL value of their work in demonstrating that there most definitely IS an alternative to our current lifestyles - discount those facts. And of course, that's made all the more critical by the impact of your first point; it AIN'T EVEN going to be as simple as simply rewinding the clock.

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