IPB

Welcome Guest ( Log In | Register )

5 Pages V   1 2 3 > »   
Reply to this topicStart new topic
Enceladus Jet Sources
ugordan
post Oct 10 2007, 05:20 PM
Post #1


Senior Member
****

Group: Members
Posts: 3563
Joined: 1-October 05
From: Croatia
Member No.: 523



New press release by the imaging team:

Cassini Pinpoints Hot Sources of Jets on Enceladus
October 10, 2007
(Source: Space Science Institute)

CICLOPS link to the release here.

One thing I was curious about tiger stripe naming - why didn't they switch "Baghdad" and "Cairo" so we have a nice A,B,C,D progression? I can only imagine it was done on purpose, but why?


--------------------
Go to the top of the page
 
+Quote Post
volcanopele
post Oct 10 2007, 05:27 PM
Post #2


Senior Member
****

Group: Moderator
Posts: 2860
Joined: 11-February 04
From: Tucson, AZ
Member No.: 23



Joe Spitale and Carolyn Porco have a paper in Nature, out tomorrow but online today, on the sources of Enceladus' South Polar jets entitled, "Association of the jets of Enceladus with the warmest regions on its south-polar fractures." As you can tell from the title, many of the jet sources are located near hotspots seen by CIRS, and nearly all are located along one of the tiger stripes in the south polar region. For those without access to the article, there is a press release located at http://saturn.jpl.nasa.gov/news/press-rele....cfm?newsID=780 . In addition, a map showing the hotspot and jet source locations can be found at http://photojournal.jpl.nasa.gov/catalog/PIA08385 . These are really intriguing results, and it would be interesting to see how these sources match up with those of the jets seen a couple of weeks ago. Are the sources variable? Are different parts of the stripes active at different times (as Terry Hurford suggests) or are they more constant and tied to thermal emission sites (as Spitale and Porco suggest)?

Enjoy!


--------------------
&@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io
Go to the top of the page
 
+Quote Post
belleraphon1
post Dec 17 2007, 10:38 PM
Post #3


Member
***

Group: Members
Posts: 724
Joined: 29-December 05
From: NE Oh, USA
Member No.: 627



All..

I had seen this earlier in the AGU Abtracts but declined to post until we had some fuller reporting.
Unfortunately, this is all that has came forward so far.....


"Sodium issue clouds Enceladus"
http://news.bbc.co.uk/2/hi/science/nature/7145530.stm

quoting from this press release....

"A chemical analysis of Enceladus, led by University of Colorado planetary scientist Nick Schneider, failed to detect sodium, an element scientists say should be in a body of water that has had billions of years of contact with rock.

"If you have a long-lived ocean, it's going to have salt in it," said Dr Schneider, at the American Geophysical Union (AGU) meeting in San Francisco this week, "but that ocean, if it exists on Enceladus, isn't leaking out into space."

"Critics of the study accept his observations, but disagree with his conclusion; and it has led to some robust exchanges here at the AGU meeting this past week. "

March flyby through the plumes is gonna be really interesting....

Craig
Go to the top of the page
 
+Quote Post
scalbers
post Dec 18 2007, 12:10 AM
Post #4


Member
***

Group: Members
Posts: 805
Joined: 5-March 05
From: Boulder, CO
Member No.: 184



Interesting to see this sodium discussion continuing. There was also robust discussion after a similar talk by Nick Schneider at the August Outer Planet Satellites workshop.


--------------------
Go to the top of the page
 
+Quote Post
belleraphon1
post Dec 18 2007, 01:37 AM
Post #5


Member
***

Group: Members
Posts: 724
Joined: 29-December 05
From: NE Oh, USA
Member No.: 627



Very interesting indeed.

No Saknussemm Sea? (called this in the movie, not the book.... but it sounds better)
http://www.online-literature.com/verne/jou...enter_earth/30/


Cold Faithful - high temperature source for plumes
http://www.planetary.org/news/2007/0322_Ch...est_a_Soup.html
http://www.sciencenews.org/articles/20060506/bob9.asp
The process that converts NH3 to N2 and also creates CH4 through serpentization, involves reaction with a silicate core. Hard to see how the salts would be segregated out of the plumes.

Are the salts all in a non-ionized state and invisible? Can INMS detect salts?

Frigid Faithful - low temperature source for plumes
http://www.planetary.org/news/2006/1214_Ne..._Plumes_on.html
Are the organics at the plume sources captured from other sources in the Saturn system? Or primordial leftovers, not endogenic?

curiouser and curiouser....

Enceladus ain't easy..

Glorious....

Craig
Go to the top of the page
 
+Quote Post
DFortes
post Dec 18 2007, 01:27 PM
Post #6


Junior Member
**

Group: Members
Posts: 26
Joined: 11-April 07
From: London, U.K.
Member No.: 1957



Yet another Enceladus plume model
Go to the top of the page
 
+Quote Post
belleraphon1
post Dec 19 2007, 12:44 AM
Post #7


Member
***

Group: Members
Posts: 724
Joined: 29-December 05
From: NE Oh, USA
Member No.: 627



Dfortes... Clathrate Faithful? (Although Frigid Faithful also depends on clathrates, I believe)

Very interesting, sir.

I have to assume you are the autthor of this paper?

The paper mentions hydrothermal processing ..... as these xenoliths migrate upwards, would they drag "salts" up with them as well?

As much as I want that ocean to be there, the sodium issue makes me pause. What is really going on here, and what is the plume source? And what powers it?


Craig
Go to the top of the page
 
+Quote Post
nprev
post Dec 19 2007, 12:59 AM
Post #8


Senior Member
****

Group: Moderator
Posts: 7004
Joined: 8-December 05
From: Los Angeles
Member No.: 602



Interesting indeed. Did the Keck observations search for any other elemental signatures other then Na, or was this even practical?


--------------------
A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
Go to the top of the page
 
+Quote Post
DFortes
post Dec 19 2007, 07:17 AM
Post #9


Junior Member
**

Group: Members
Posts: 26
Joined: 11-April 07
From: London, U.K.
Member No.: 1957



QUOTE (belleraphon1 @ Dec 19 2007, 01:44 AM) *
Dfortes... Clathrate Faithful? (Although Frigid Faithful also depends on clathrates, I believe)

Very interesting, sir.

I have to assume you are the autthor of this paper?

The paper mentions hydrothermal processing ..... as these xenoliths migrate upwards, would they drag "salts" up with them as well?

As much as I want that ocean to be there, the sodium issue makes me pause. What is really going on here, and what is the plume source? And what powers it?


Craig



Thanks, yeah it's mine. I originally (in a moment of wholly uncharacteristic cynicism) called it tepid faithful. Settled on frothy faithful in the end. The difference with the existing clathrate model is that dissociation occurs in warm rising cryomagma whereas the Kieffer model is entirely dry.

As for the sodium - it is not obvious to me that this rules out the presence of an ocean. I would expect any salts to be carried in aqueous solution and be partitioned into hydrated crystalline phase on eruption, so you would not see the expected spectral signature. In the near IR these hydrated salts will appear similar to ice. Whether or not these salts would become coloured after radiation processing I do not know. Sputtering might yield a small flux of cations - depends on the salt; might be Na, Mg, NH4 etc...

Dom
Go to the top of the page
 
+Quote Post
belleraphon1
post Dec 19 2007, 01:21 PM
Post #10


Member
***

Group: Members
Posts: 724
Joined: 29-December 05
From: NE Oh, USA
Member No.: 627



QUOTE (DFortes @ Dec 19 2007, 02:17 AM) *
Thanks, yeah it's mine. I originally (in a moment of wholly uncharacteristic cynicism) called it tepid faithful. Settled on frothy faithful in the end. The difference with the existing clathrate model is that dissociation occurs in warm rising cryomagma whereas the Kieffer model is entirely dry.

As for the sodium - it is not obvious to me that this rules out the presence of an ocean. I would expect any salts to be carried in aqueous solution and be partitioned into hydrated crystalline phase on eruption, so you would not see the expected spectral signature. In the near IR these hydrated salts will appear similar to ice. Whether or not these salts would become coloured after radiation processing I do not know. Sputtering might yield a small flux of cations - depends on the salt; might be Na, Mg, NH4 etc...

Dom


Frothy Faithful... I LIKE that.

Thanks for the clarification between the Frothy and Frigid models, Dom. And your take on the sodium issue. I feel a little more reassured regarding an ocean. smile.gif

UMSF is greatly enriched by having researchers and mission ops folks among it's members.

Thanks again.

Craig
Go to the top of the page
 
+Quote Post
Guest_Zvezdichko_*
post Feb 8 2008, 07:17 PM
Post #11





Guests






http://saturn.jpl.nasa.gov/news/features/feature20080207.cfm - Enceladus plume model... scientists suggest an underground lake.
Go to the top of the page
 
+Quote Post
ustrax
post Mar 6 2008, 04:27 PM
Post #12


Special Cookie
****

Group: Members
Posts: 2168
Joined: 6-April 05
From: Sintra | Portugal
Member No.: 228



March 12 flyby description available at Ciclops. smile.gif


--------------------
"Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe
Go to the top of the page
 
+Quote Post
scalbers
post Mar 22 2008, 06:23 PM
Post #13


Member
***

Group: Members
Posts: 805
Joined: 5-March 05
From: Boulder, CO
Member No.: 184



Here's a nice powerpoint I came across about Enceladus and its heating - by Tanya Harrison. The pros and cons of the liquid H2O vs clathrate hypotheses are summarized.

http://mgilmore.web.wesleyan.edu/wescourse...1/enceladus.ppt


--------------------
Go to the top of the page
 
+Quote Post
MahFL
post Jun 13 2008, 01:53 PM
Post #14


Forum Contributor
***

Group: Members
Posts: 955
Joined: 8-February 04
From: North East Florida, USA.
Member No.: 11



From http://ciclops.org/index.php
"And most exciting of all: the highest temperatures now measured are about 180 Kelvins, some 63 degrees Fahrenheit warmer than estimated from previous measurements. Though by no means a guarantee, these results make the possibility of liquid water close to the surface of the moon even more likely. Sacre bleu!..."

Water water everywhere !!!!!
Go to the top of the page
 
+Quote Post
tasp
post Jun 13 2008, 03:26 PM
Post #15


Member
***

Group: Members
Posts: 885
Joined: 30-January 05
Member No.: 162



Maybe . . . .

no, probably not.
Go to the top of the page
 
+Quote Post

5 Pages V   1 2 3 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 2nd September 2014 - 11:52 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.