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Enceladus Plume Search, Nov. 27
jmknapp
post Nov 24 2005, 04:01 PM
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Interesting item in the science plan kernel (S16) just released to the NAIF website:

OBSERVATION_ID: S1629

SEQUENCE: S16

OBSERVATION_TITLE: Plume Search

SCIENCE_OBJECTIVE: Hope to detect/observe plumes, whether from volcanic activity or geysers.

OBS_DESCRIPTION: Point and stare.

SUBSYSTEM: ISS

PRIMARY_POINTING: ISS_NAC to Enceladus (0.0,5.0,0.0 deg. offset)

REQUEST_ID: ISS_018EN_PLUMES001_PRIME

REQUEST_TITLE: ENCELADUS Geyser/Plume Search

REQ_DESCRIPTION: 1;ENCELADUS Geyser/Plume Search 1x1xNPp -- 3 different exposures

BEGIN_TIME: 2005 NOV 27 19:00:00 UTC

END_TIME: 2005 NOV 27 20:00:00 UTC


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dvandorn
post Dec 2 2005, 08:14 AM
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The question that comes to my mind is:

If "warm" ice is convecting towards Enceladus' surface and then fountaining out of these south polar vents in significant quantities, could this have been happening for a very large percentage of Enceladus' existence?

Do we have any clue of how much mass is entrained in the E ring? And can we even estimate the rate of mass lost from Enceladus due to this process? Because, for example, even if it's only losing a few tons of material a day, after billions of years, such venting would significantly reduce the mass and size of the body. And what would happen to an icy moon that has lost a significant amount of mass from within -- wouldn't there be signs of global crustal compression?

I guess it depends on what's heating the interior ice and forcing convection of "warm ice" to the surface. Since tidal heating seems unlikely for such a small body, perhaps it's radiogenic? Maybe Enceladus happened to form around a rocky core that, for some as-yet-unguessed reason, had an anomalous amount of radiogenic minerals within it?

If that's the case, then maybe Enceladus started out a lot bigger and has been losing mass -- and size -- for billions of years. Otherwise, you'd have to think that the activity we're seeing now is relatively rare, and we're lucky to be seeing it...

-the other Doug


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jmknapp
post Dec 2 2005, 11:18 AM
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Interesting comments from Dr. Carolyn Porco:

"We suspect it could be caused by cold vents that lead from somewhere in the subsurface, perhaps as far as 1 kilometer down. Water ice is sublimating (changing directly from a solid to a gas state) and the vapors are coming off and building up to high pressure." http://dsc.discovery.com/news/briefs/20051...eladus_spa.html

Since the e-ring has been determined to be particulate, maybe these sublimating water vapor jets have enough pressure to pick up ice particles and send them into space with escape velocity?

Based on a web calculator I get 240 m/sec for escape velocity at the surface of Enceladus.

Also from the article:

"What's puzzling us is how it's getting hot enough," Porco said. "We're still in a quandary over how you'd get this much energy."


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ugordan
post Dec 2 2005, 11:50 AM
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QUOTE (jmknapp @ Dec 2 2005, 12:18 PM)
Interesting comments from Dr. Carolyn Porco:

"We suspect it could be caused by cold vents that lead from somewhere in the subsurface, perhaps as far as 1 kilometer down. Water ice is sublimating (changing directly from a solid to a gas state) and the vapors are coming off and building up to high pressure." http://dsc.discovery.com/news/briefs/20051...eladus_spa.html

So they're more or less abanoning the idea of there actually being liquid water below?

QUOTE (jmknapp @ Dec 2 2005, 12:18 PM)
Based on a web calculator I get 240 m/sec for escape velocity at the surface of Enceladus.

Views of the solar system says 212 m/s, so that's probably about it. It doesn't mean the ice particles need to have this velocity to escape Enceladus, this figure is a theoretical speed needed for an object to reach infinity from the surface. In reality, Saturn's gravitation is bound to take over long before that so the real escape velocity could be substantially lower than that.


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Posts in this topic
- jmknapp   Enceladus Plume Search, Nov. 27   Nov 24 2005, 04:01 PM
- - jmknapp   Here's the view of Enceladus during the plume ...   Nov 26 2005, 11:02 PM
|- - ElkGroveDan   QUOTE (jmknapp @ Nov 26 2005, 11:02 PM)Here...   Nov 27 2005, 12:15 AM
||- - David   QUOTE (ElkGroveDan @ Nov 27 2005, 12:15 AM)Lo...   Nov 28 2005, 11:54 PM
|- - dilo   Thanks for all these informations, jmknapp (also i...   Nov 27 2005, 08:04 AM
|- - jmknapp   QUOTE (dilo @ Nov 27 2005, 04:04 AM)Really ho...   Nov 27 2005, 02:13 PM
|- - mgrodzki   that is a nice image… not color right? and i assum...   Nov 27 2005, 06:24 PM
|- - dilo   QUOTE (mgrodzki @ Nov 27 2005, 06:24 PM)that ...   Nov 28 2005, 06:41 AM
- - Decepticon   Images Up. http://saturn1.jpl.nasa.gov/multimed...   Nov 28 2005, 01:10 PM
|- - SFJCody   http://saturn1.jpl.nasa.gov/multimedia/ima...6/N00...   Nov 28 2005, 01:29 PM
- - alan   Possible plume? Doesn't look like a lens flare...   Nov 28 2005, 01:31 PM
|- - ugordan   QUOTE (alan @ Nov 28 2005, 03:31 PM)Possible ...   Nov 28 2005, 01:38 PM
|- - Bjorn Jonsson   This is the first time I see something like this t...   Nov 28 2005, 01:49 PM
|- - tedstryk   I am at work, or I would do this myself, but someo...   Nov 28 2005, 02:12 PM
|- - Bjorn Jonsson   QUOTE (tedstryk @ Nov 28 2005, 02:12 PM)I am ...   Nov 28 2005, 02:18 PM
- - Decepticon   Is there enough pics for a animation?   Nov 28 2005, 02:14 PM
- - Mariner9   ohmygod!!!!!!!!...   Nov 28 2005, 03:10 PM
- - Bill Harris   Whew. I'm not as up on the entire archive of ...   Nov 28 2005, 03:21 PM
|- - jmknapp   Too bad there isn't plume evidence on the dark...   Nov 28 2005, 03:27 PM
|- - ugordan   QUOTE (jmknapp @ Nov 28 2005, 05:27 PM)Too ba...   Nov 28 2005, 03:32 PM
||- - jmknapp   QUOTE (ugordan @ Nov 28 2005, 11:32 AM)Well, ...   Nov 28 2005, 03:44 PM
||- - ugordan   QUOTE (jmknapp @ Nov 28 2005, 05:44 PM)But an...   Nov 28 2005, 03:51 PM
||- - jmknapp   QUOTE (ugordan @ Nov 28 2005, 11:51 AM)Why do...   Nov 28 2005, 03:59 PM
||- - tedstryk   QUOTE (jmknapp @ Nov 28 2005, 03:59 PM)Not in...   Nov 28 2005, 04:49 PM
||- - jmknapp   Here's a map of the south polar region, based ...   Nov 28 2005, 05:56 PM
|||- - jmknapp   Found this image of the south polar region (approx...   Nov 28 2005, 06:41 PM
|||- - The Messenger   QUOTE (jmknapp @ Nov 28 2005, 10:56 AM)Here...   Nov 28 2005, 08:44 PM
||- - scalbers   QUOTE (tedstryk @ Nov 28 2005, 04:49 PM)I thi...   Nov 28 2005, 08:17 PM
||- - dilo   QUOTE (tedstryk @ Nov 28 2005, 04:49 PM)I thi...   Nov 28 2005, 09:03 PM
|- - JRehling   QUOTE (jmknapp @ Nov 28 2005, 07:27 AM)Too ba...   Nov 28 2005, 03:35 PM
- - tasp   What is the power source for this? {Wild speculat...   Nov 28 2005, 03:51 PM
- - Orlin Denkov   In the title of this thread isn't it Enceladus...   Nov 28 2005, 03:55 PM
- - volcanopele   ^^ Fixed   Nov 28 2005, 03:56 PM
|- - The Messenger   The source of the heat is truly perplexing. I hope...   Nov 28 2005, 04:48 PM
- - tasp   Maybe I am 'seeing' too much into your map...   Nov 28 2005, 06:29 PM
- - canis_minor   The features seen in these images are located at t...   Nov 28 2005, 07:21 PM
- - Bill Harris   The ridges and wrinkles in that region are a stron...   Nov 28 2005, 07:37 PM
|- - Bjorn Jonsson   I'm attaching a rendering I did showing the vi...   Nov 28 2005, 08:47 PM
|- - jmknapp   QUOTE (Bjorn Jonsson @ Nov 28 2005, 04:47 PM)...   Nov 28 2005, 10:01 PM
|- - mars loon   This news just released by CICLOPS website ...   Nov 28 2005, 10:31 PM
- - volcanopele   Special release for the Enceladus plume: http://c...   Nov 28 2005, 09:59 PM
|- - ugordan   QUOTE (volcanopele @ Nov 28 2005, 11:59 PM)Fo...   Nov 29 2005, 08:07 AM
- - Sunspot   What's also striking is how obvious the plumes...   Nov 28 2005, 10:48 PM
|- - mars loon   QUOTE (Sunspot @ Nov 28 2005, 10:48 PM)What...   Nov 28 2005, 11:29 PM
- - akuo   Looking at the raws I noticed that the whole backg...   Nov 28 2005, 11:29 PM
|- - EccentricAnomaly   The E-Ring is just such a donut of material around...   Nov 29 2005, 12:44 AM
- - edstrick   Regarding the plume images: Feb 20, I posted: htt...   Nov 29 2005, 07:50 AM
|- - volcanopele   QUOTE (edstrick @ Nov 29 2005, 12:50 AM)NOW.....   Nov 29 2005, 07:30 PM
|- - jmknapp   One thing that strikes me in the CICLOPS press rel...   Nov 29 2005, 08:08 PM
- - BruceMoomaw   Crowing about one's foresight is bad manners, ...   Nov 29 2005, 08:23 AM
- - edstrick   (grins a bit toothily at Bruce Moomaw, canary feat...   Nov 29 2005, 08:39 AM
- - Gsnorgathon   Good for you, Ed! Crow all you like! (Actu...   Nov 29 2005, 10:52 AM
- - edstrick   I doubt there's enough parallax during the hig...   Nov 29 2005, 11:55 AM
|- - ugordan   Regarding the possibility of more intense Enceladu...   Nov 29 2005, 12:16 PM
|- - jmknapp   We're set for a Christmas rerun: The above ...   Nov 29 2005, 02:18 PM
||- - ugordan   QUOTE (jmknapp @ Nov 29 2005, 03:18 PM)The ab...   Nov 29 2005, 02:33 PM
||- - jmknapp   QUOTE (ugordan @ Nov 29 2005, 10:33 AM)That...   Nov 29 2005, 03:40 PM
|- - The Messenger   QUOTE (ugordan @ Nov 29 2005, 05:16 AM)Option...   Nov 29 2005, 05:18 PM
|- - jmknapp   QUOTE (ugordan @ Nov 29 2005, 08:16 AM)Regard...   Nov 30 2005, 01:59 AM
- - Omega   Regarding possible artifact-- QUOTE Images of oth...   Nov 29 2005, 05:53 PM
- - scalbers   My guess is that the rays are actual streamers of ...   Nov 29 2005, 08:44 PM
|- - Rob Pinnegar   QUOTE (scalbers @ Nov 29 2005, 02:44 PM)My gu...   Nov 29 2005, 09:20 PM
|- - Marz   QUOTE (scalbers @ Nov 29 2005, 02:44 PM)Would...   Nov 29 2005, 09:20 PM
|- - JRehling   QUOTE (scalbers @ Nov 29 2005, 12:44 PM)My gu...   Nov 29 2005, 09:21 PM
|- - tedstryk   This makes me wonder about Europa, where high phas...   Nov 29 2005, 11:44 PM
- - BruceMoomaw   QUOTE (jmknapp @ Nov 29 2005, 08:08 PM)If it ...   Nov 30 2005, 03:00 AM
|- - tedstryk   Galileo came up cold, but Europa is much bigger, a...   Nov 30 2005, 03:54 AM
|- - The Messenger   QUOTE (BruceMoomaw @ Nov 29 2005, 08:00 PM).....   Nov 30 2005, 04:34 AM
- - edstrick   Various comments and responses: Looking at jmknap...   Nov 30 2005, 06:24 AM
|- - jmknapp   QUOTE (edstrick @ Nov 30 2005, 02:24 AM)Vario...   Nov 30 2005, 01:24 PM
||- - ugordan   QUOTE (jmknapp @ Nov 30 2005, 02:24 PM)Intere...   Nov 30 2005, 01:38 PM
||- - jmknapp   QUOTE (ugordan @ Nov 30 2005, 09:38 AM)Of cou...   Nov 30 2005, 04:48 PM
|- - The Messenger   QUOTE (edstrick @ Nov 29 2005, 11:24 PM)What ...   Dec 1 2005, 03:17 AM
- - edstrick   And, Oh... from the Utter Loonacy Department. M...   Nov 30 2005, 06:29 AM
- - Webscientist   Astonishing news, I'm really surprised to see ...   Nov 30 2005, 09:36 AM
- - Bill Harris   > from the Utter Loonacy Department... Aye, Ca...   Nov 30 2005, 10:42 AM
- - BruceMoomaw   That last quote was actually a misinterpretation b...   Dec 1 2005, 12:33 AM
|- - mars loon   QUOTE (BruceMoomaw @ Dec 1 2005, 12:33 AM)Wha...   Dec 1 2005, 12:48 AM
|- - ugordan   QUOTE (BruceMoomaw @ Dec 1 2005, 01:33 AM)Wha...   Dec 1 2005, 08:39 AM
|- - jmknapp   QUOTE (BruceMoomaw @ Nov 30 2005, 08:33 PM)Th...   Dec 1 2005, 12:23 PM
|- - jmknapp   Closeups of the tiger stripes are intriguing but a...   Dec 1 2005, 01:08 PM
- - deglr6328   There is a second derivative of two ammonia absorp...   Dec 1 2005, 09:14 AM
- - edstrick   Ugordan: "....but haven't there been some...   Dec 1 2005, 11:28 AM
- - dvandorn   Based on the shadows, the sun is on the *right*......   Dec 1 2005, 01:14 PM
|- - jmknapp   QUOTE (dvandorn @ Dec 1 2005, 09:14 AM)Based ...   Dec 1 2005, 01:22 PM
|- - ugordan   QUOTE (jmknapp @ Dec 1 2005, 02:22 PM)So the ...   Dec 1 2005, 02:04 PM
- - dvandorn   In the context image, your point is clear... but g...   Dec 1 2005, 02:18 PM
|- - jmknapp   QUOTE (dvandorn @ Dec 1 2005, 10:18 AM)In the...   Dec 1 2005, 02:40 PM
- - David   Enceladus is the "shiniest" moon in the ...   Dec 1 2005, 02:47 PM
|- - ugordan   QUOTE (David @ Dec 1 2005, 03:47 PM)Enceladus...   Dec 1 2005, 02:55 PM
- - Bill Harris   QUOTE (jmknapp @ Dec 1 2005, 08:40 AM)It...   Dec 1 2005, 04:09 PM
- - tasp   How fast are these plumes turning Enceladus inside...   Dec 1 2005, 05:01 PM
|- - ugordan   QUOTE (tasp @ Dec 1 2005, 06:01 PM)Any chance...   Dec 2 2005, 08:10 AM
- - dvandorn   The question that comes to my mind is: If "w...   Dec 2 2005, 08:14 AM
- - jmknapp   Interesting comments from Dr. Carolyn Porco: ...   Dec 2 2005, 11:18 AM
- - ugordan   QUOTE (jmknapp @ Dec 2 2005, 12:18 PM)Interes...   Dec 2 2005, 11:50 AM
- - jmknapp   QUOTE (ugordan @ Dec 2 2005, 07:50 AM)So they...   Dec 2 2005, 11:57 AM
- - ugordan   Regarding the source of the heat, there is a relat...   Dec 2 2005, 12:15 PM
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