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Plumes from Enceladus detected?
From the latest batch of Cassini images:
Looks rather convincing! The plumes seem to originate from the "tiger stripe" area, which is known to be very young and geologically active.
If the plumes are indeed real, Enceladus will be only the fourth body in our Solar system, where volcanism has been seen in action!
However, just looking these pictures overexposure or similar image blemishes can't be totally excluded.
Last edited by Kullat Nunu; 2005-Dec-20 at 05:27 PM.
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Another view with a longer exposure:
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Notice how Cassini has rotated between the exposures, but the plumes stay at fixed position relative to Enceladus. This is a strong evidence for volcanic plumes.
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Ack - you beat me to that by the two minutes I spent checking the simulator. Obvious image artifacts can be ruled out by the multiple images at different angular orientations, and it's not that the Sun is actually behind Enceladus and Saturn illuminating it or anything. That would make the backlighting from the outer corona, if I get the geometry right. This is quite a coup for the Cassini team - watch for these in the newscasts!Originally Posted by Kullat Nunu
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Wow, this is big news....we need to send a orbiter there soon...that would be cool.
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Fountains of Enceladus
http://ciclops.org/view.php?id=1688
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So now we need to figure out *why* Enceladus is active in this way, and why (to me anyway) it seems that so many of Saturn's moons have experienced some sort of geological activity.
I wonder if this is related to the preponderance of very large craters that can be found on many Saturnian moons.
...John...
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Well,
You all seem happy with the "ice volcano" explanation, but to me it seems very unlikely that volcanic plumes can be ejected under an angle from Enceladus' surface. Besides, the temperature difference measured at the "tiger stripes" is not very high, how can it generate any "fountains"? They look more like streamers, pity they don't have a time-lapse movie, it could show how the wispy streamers really move. I think they are more akin to cometary jets, or even the streamers visible above the solar surface.
Cheers.
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Cassini news release: Multiple Cassini Instruments Capture Enceladus Plume
VIMS instrument has detected the plumes of Enceladus and has confirmed that the moon is the source of the E ring.
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I agree with VanderL. Cometary jets are a more apt description than volcanoes. When I think of volcanoes, I think of a big mountain with a crater on top. Considering the gravity of Enceladus, a geyser such as Old Faithful would would blast water vapour into the E ring.
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Did anyone notice the similarity between Enceladus' tail and Prometheus' tail?
Prometheus was thought to "steal" material from one of the rings, but unless we have some time-lapse images they could very well be similar to the jets from Enceladus. Detailed analysis could verify their cometary nature (filaments and streamers). Of course sunlight can't be responsible, but Saturn has a strong magnetosphere present throughout the rings and moons.
Cheers.
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You might want to hold off on plans for that ice-fishing trip to Enceladus.
University of Illinois press release: Scientists propose alternate model for plume on Enceladus
Initial reports speculated that chambers of liquid water lay close to the moon’s surface and erupted in a giant geyser. The water would be near freezing, so scientists dubbed the model “Cold Faithful,” after the familiar, but hotter, Old Faithful geyser in Yellowstone National Park.
“A problem with this model,” Kieffer said, “is that 10 percent of the plume consists of the gases carbon dioxide, nitrogen and methane. You might get a carbon dioxide-driven liquid geyser there, but you can’t put this much nitrogen and methane into liquid water at the low pressures found inside Enceladus.”
Nitrogen and methane are nearly insoluble in liquid water, but highly soluble in frozen water – in an ice phase called clathrate. When clathrate is exposed to a vacuum, the gas molecules burst out, ripping the ice lattice to shreds and carrying the fragments away.
Kieffer and colleagues have proposed an alternate model to explain the plume on Enceladus. The gases in the plume, they propose, are dissolved in a reservoir of clathrate under the water ice cap in the south polar region. The clathrate model allows an environment that would be 80 to 100 degrees Celsius colder than liquid water, with a “Frigid Faithful” plume emanating from clathrates, rather than from liquid water reservoirs.
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This seems to open up another question, though (doesn't it always?)
What is causing the clathrates to migrate to the surface and being exposed to vacuum?
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Very interesting information HERE
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So I guess you could describe them as Solid State geysers
Banned
For fear of being banned, as per the warning HERE, mods can move to the ATM, but
tp://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276This astonishing, never-before-seen structure is made visible with the sun almost directly behind the Saturn system from Cassini's vantage point. The sun-Enceladus-spacecraft angle here is 175 degrees, a viewing geometry in which structures made of tiny particles brighten substantially.
These features are very likely the result of particles injected into Saturn orbit by the Enceladus geysers: Those injected in the direction of the moon's orbital motion end up on larger, slower orbits and trail Enceladus in its orbit, and those injected into the opposite direction end up smaller, faster orbits and lead Enceladus. (Orbital motion is counter-clockwise.) In addition, the configuration of wisps may hint at an interaction between Saturn's magnetosphere and the torrent of particles issuing from Enceladus.
These are not the people to propose something ATM, are they?
Confused
Banned
For fear of being banned, as per the warning ttp://www.bautforum.com/showthread.php?t=51038, mods can move it to the ATM section, but...
tp://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276This astonishing, never-before-seen structure is made visible with the sun almost directly behind the Saturn system from Cassini's vantage point. The sun-Enceladus-spacecraft angle here is 175 degrees, a viewing geometry in which structures made of tiny particles brighten substantially.
These features are very likely the result of particles injected into Saturn orbit by the Enceladus geysers: Those injected in the direction of the moon's orbital motion end up on larger, slower orbits and trail Enceladus in its orbit, and those injected into the opposite direction end up smaller, faster orbits and lead Enceladus. (Orbital motion is counter-clockwise.) In addition, the configuration of wisps may hint at an interaction between Saturn's magnetosphere and the torrent of particles issuing from Enceladus.
These are not the people to propose something ATM, are they?
Confused
Awesome photo!
Administrator
It is one thing to say there is an interaction between the plumes and the magnetosphere of Saturn, and a much more ATM thing to link to Thunderbolts and give a straight EU explanation saying that somehow there is a huge current between the two objects because the moon is highly charged.
I'm not sure why you are posting this, whether you are questioning the moderation policies, or hoping for a clearly defined line that you shouldn't cross (you won't get one), or some other reason. But this line of questioning is off-topic. If you want to discuss the plumes of Enceladus, lets keep talking. If you want to discuss EU, move it to the ATM section. If you want to discuss moderation policy, open a thread in About BAUT.
Forming opinions as we speak
Banned
Don't recall linking to Thunderbolts, do they have a good explination?
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You didn't link to it, but you were wondering about the warning that larryduane100 got, and wanted to know what made his post sufficiently ATM to get a warning. As to whether that site has explanations, I disagree with most of their conclusions, but we have a core group of ATM supporters who seem to reference it. Judge for yourself, but if you like it, please only reference it in the ATM section.
Forming opinions as we speak
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NASA Cassini-Huygens Mission News: A Hot Start Might Explain Geysers on Enceladus
A new model suggests the rapid decay of radioactive elements within Enceladus shortly after it formed may have jump-started the long-term heating of the moon's interior that continues today. The model provides support for another recent, related finding, which indicates that Enceladus' icy plumes contain molecules that require elevated temperatures to form.
"Enceladus is a very small body, and it's made almost entirely of ice and rock. The puzzle is how the moon developed a warm core," said Dr. Julie Castillo, the lead scientist developing the new model at JPL. "The only way to achieve such high temperatures at Enceladus is through the very rapid decay of some radioactive species."
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NASA Cassini-Huygens Mission News: Cassini Pinpoints Hot Sources of Jets on Enceladus
A recent analysis of images from NASA's Cassini spacecraft provides conclusive evidence that the jets of fine, icy particles spraying from Saturn's moon Enceladus originate from the hottest spots on the moon's "tiger stripe" fractures that straddle the moon's south polar region.
[...]
"These are findings with tremendously exciting implications and to say that I am eager to get to the bottom of it would be a cosmic understatement," said Porco. "Do the jets derive from near-surface liquid water or not? And if not, then how far down is the liquid water that we all suspect resides within this moon? Personally, I'd like to know the answer yesterday!"
The next opportunity for answering these questions will be when Cassini dips low over Enceladus and flies through the plumes in March 2008, obtaining additional data about its chemical composition and the nature of its jets.
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I am such an idiot. I kept pronouncing that moon's name as en-clay-deus.
That would sound cooler...
Banned
So have I. Two idiots.
I wonder now how many other things I'm pronouncing all wrong?
And of course, nobody's gonna tell me. Just smile and nod. Let me look ignorant.
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Nineplanets.org :: Enceladus:
Browse away.Enceladus ("en SEL a dus") is the eighth of Saturn's known satellites
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Most people I've heard talk about it say en-cel-AH-dus.
But how should I know, I still say UOR-ahn-us.
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
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This thread reminds me of that animation of the ice volcano-- I think it was on Callisto? I tried to search but couldn't find it. Anyone know which one I'm talking about? Anyone? Beuller?
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
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There's not many bodies in the system with known active volcanoes.
Enceladus? Though it might seem more like a geyser. Cryovolcano, if you will.
Active Volcanoes of Our Solar System
Enceladus Plume MovieObserved recent eruptions are limited to Earth and three other locations: 1) Io, a moon of Jupiter; 2) Triton, a moon of Neptune; and, 3) Enceladus, a moon of Saturn.
The most dramatic recent volcano movie was Tvashtar on Io, by New Horizons, but it's not an ice volcano.
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It was that one. Id'oh!
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
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