Gravitational tide the secret of Saturn's weird moon

Jul 31, 2013
Enceladus

Enceladus, a white moon of Saturn with ice-spewing volcanoes, owes its strangeness to tides of gravitational forces exerted by its mother, a study in Nature said on Wednesday.

Discovered in 1789 by William Herschel, Enceladus measures only 504 kilometres (315 miles) across yet is one of the great oddities of the Solar System.

Its surface is a gorgeous white shell of ice, rather than asteroid-pocked rock and dust, and the surface is pristine except for a network of fractures near its south pole.

These cracks—dubbed "tiger stripes"—emit fountains of water vapour that instantly turn into icy grains on contact with the chill vacuum of space. Some astrophysicists conclude that the worldlet harbours an ocean of saltwater, which in turn makes it a good candidate as a source for life. But how can a sub-surface sea exist, if the ambient temperature is close to absolute zero—-273 degrees Celsius (-460 degrees Fahrenheit)—and the Sun is a distant dot?

The answer, say theorists, lies with a phenomenon called tidal forces. They argue that the gravitational pull exerted by Saturn, the second largest planet of the Solar System, squeezes Enceladus' innards, causing friction whose heat allows the water to remain in a liquid state.

Long debated, the notion has now gained the support of comparisons of the icy plume as the moon crawls around Saturn on an egg-shaped orbit.

When Enceladus is closest to Saturn, the plume is at its dimmest, a sign that the fractures are being closed up by a mighty gravitational pull from the giant mother plant, and so relatively little water escapes, according to the new study.

When Enceladus is at its farthest point from Saturn, the plume is several times brighter, suggesting that the fractures open out—rather like an unclenched fist—and more water is disgorged. The evidence comes from 252 infra-red images taken by the great US explorer probe Cassini during its lonely swings around the planet.

They provide "strong evidence that tidal forces do play an important role in controlling Enceladus' plume activity, perhaps by changing the width of the conduits between the surface and various underground reservoirs," says the paper, led by Matthew Hedman of Cornell University in New York. Many of the icy grains from Enceladus fall back on its surface, which explains its dazzling white surface.

The ice may also be the origin of one of the rings of Saturn that give the gas giant its special beauty, according to some thinking.

Explore further: Space station's 3-D printer pops out 1st creation

More information: Paper: dx.doi.org/10.1038/nature12371

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User comments : 13

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cantdrive85
1.3 / 5 (13) Jul 31, 2013
The electric currents observed on Jovian moons;
http://hubblesite...image/a/

Have also been detected between Enceladus and Saturn;
http://www.nasa.g...069.html

As with IO, Enceladus' activity is due to a small charged sphere orbiting an energetic plasma environment. As that circuit flows through the moon, just as on Io, the currents are "focused" as they flow into and out of the solid material, thus creating a plasma focus discharge.
http://www.plasma...sler.pdf

It is also known, plasma tokamaks and arc discharge produce produce highly electrodynamic nanodust/nanotubes;
http://www.plasma...sTPS.pdf

It would seem electric discharge of plasma and ionized gases explains this phenomena far better than the already failed theory of tidal kneading.

http://phys.org/n...ong.html
Thnder
5 / 5 (1) Jul 31, 2013
Should get something out there to take samples from the plume.
cantdrive85
1.3 / 5 (13) Jul 31, 2013
They did;
http://www.jpl.na...2008-050

And somewhat surprising to them, it "tasted and smelled" like a comet. This is not surprising to the electric model, the plumes of Io and Enceladus are created by similar plasma arc discharges that comets experience.
cantdrive85
1.3 / 5 (12) Jul 31, 2013
It seems the electrodynamic nanodust theory mentioned above has been well supported by in situ data;
http://www.nasa.g...531.html

Oddly, once again dogma reigns when you read the article. The scientists continue with their mistaken assumptions. The scientist remarked;
"Such strong coupling indicates the possible presence of so-called 'dusty plasma', rather than the 'dust in a plasma' conditions which are common in interplanetary space," then; "Except for measurements in Earth's upper atmosphere, there have previously been no in-situ observations of dusty plasma in space."
Rather than questioning whether his 'dust in plasma' belief is correct and accepting the in situ data, along with lab findings of plasma behavior he clings to his dogma.

It continues;
"based on data obtained by the Cassini plasma spectrometer, revealed the presence of nanograins having an electric charge"

This will likely be found wherever there is dust.
Gmr
2.2 / 5 (13) Jul 31, 2013
Scientist: "We've got some interesting new calculations having to do with an explanatory model that predicts a lot of these features, based on orbital mechanics, tidal differentials and heating, and the LaRoche limit."

PhysOrg article author: "squeezes Enceladus' innards"

PhysOrg commentator: "Electric derp! Electric predicted innards!"

I hate and love this place at the same time.
cantdrive85
1.4 / 5 (11) Aug 01, 2013
Scientist: "We've got some interesting new calculations having to do with an explanatory model that predicts a lot of these features, based on orbital mechanics, tidal differentials and heating, and the LaRoche limit."


Yep, and he probably started his study before the Io findings were released indicating a busted theory. He didn't get the memo, but since he was paid anyway he may as well release his nonsense.

Gmr
2.3 / 5 (12) Aug 01, 2013
Yep, and he probably started his study before the Io findings were released indicating a busted theory. He didn't get the memo, but since he was paid anyway he may as well release his nonsense.


Any time I think I'm maybe a bit arrogant, I come here for a little nibble of Schadenfreude. Just a little nibble, though. Too much and I'll be sick. No, just a smidge, that slice is too big.

Oh, soooo rich.
GSwift7
1.7 / 5 (6) Aug 01, 2013
It seems the electrodynamic nanodust theory mentioned above has been well supported by in situ data

Oddly, once again dogma reigns when you read the article. The scientists continue with their mistaken assumptions


From Bill Buckley (professional talking head guy):

"I will not insult your intelligence by presuming to think that you actually believe what you just said."

Unfortunately, I don't think that applies here.
Torbjorn_Larsson_OM
4.4 / 5 (5) Aug 01, 2013
That Enceladus lies in the tidal habitable zone of a giant will help map the THZ. It is nice that of the three habitable volumes (surface, ocean, crust), at least two of them form habitable zones around stars and planets.

However crustal habitability, which on ocean-less worlds is the largest, is iffier to pin down.

As for the EU trolling, which inanity can only help science education, you don't even have to know what's going on to see how insane the writers behave.

Of course it is a problem too, because it gives the impression that EM doesn't have any physical effects at all. But we know it as chemistry and so on, in some situations it is quite the player despite the impression the EUrghists puts out.

@GS7: Nice find! I haven't the energy to plow through the wrongness, but it looks like the troll is aware he isn't discussing the science. (E.g. he correctly refers to those who work in the area as scientists.)

Likely someone who gets paid by a crackpot to play a dofus.
GSwift7
3 / 5 (8) Aug 01, 2013
I haven't the energy to plow through the wrongness, but it looks like the troll is aware he isn't discussing the science. (E.g. he correctly refers to those who work in the area as scientists.)


What's really odd is that there's plenty of real plasma science in regard to Saturn and its rings and moons. There's even a double layer in the trailing plasma formation behind one of the moons. The real plasma science is easy to look up, if he wanted to do so. In stead, he just makes stuff up. He thinks he is contradicting mainstream cosmology in these cases, but in reality, these planetary systems actually follow the theories laid out by Alfven and others who did early plasma research. On planetary scale, or solar system scale, these things do apply. That's now mainstream science, so there's nothing for him to fight, unless he is trying to prove Alfven et al wrong. His exagerated version of Alfven's work is mediocre nonsense.
cantdrive85
1.4 / 5 (11) Aug 02, 2013
Ahhh, rebuttals from theoretically challenged. The main difference between PC and the theories the fellow commentators support is PC is based upon real lab supported data. Whether it be, relativity or waving bunnies it is based entirely upon theoretical belief.

"Faith means belief in something concerning which doubt is theoretically possible."

William James

Seems the faithful are out in full force.

Shelgeyr
1.3 / 5 (12) Aug 02, 2013
Amazing. @cantdrive85 presents links to evidence, reasoned theories, and rational explanations, and all his detractors can say are versions of "The proponents of Plasma Universe are the same imbeciles...", a demonstrably stupid statement on its face which reveals the shallowness of the thoughts behind it.

Once again, whether they're ultimately "proven" right or wrong, the proponents of the Plasma Universe variant theories ascribe to the philosophy of an open approach and demonstrable, repeatable evidence, while the adherents of the standard model just scream, quack, make silly faces, and cross-reference each other while claiming/believing they've offered "proof" of their fairy tales.

You mainstreamers/standard-modelers apparently wouldn't know how to question your base assumptions if they bit you, which they repeatedly do. I only say that, of course, based on repeated observations.

Science!
Gmr
1 / 5 (4) Aug 04, 2013
Oh Shelgeyr...
I'm too full. I can't eat another bite. It's tasty, sure... but too rich!

Still, I never could turn down just one more bite...

"Ironic" "Quotes" really "don't" "help" to "get" a "point" "across." The whole point is that EU/Plasma has to account for all of the success of current (pun intended) successful theories in prediction. Just demonstrate that, and /then/ move to what you/they think are "problem" "areas."

"Sorry," I couldn't "help" "myself."

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