Enceladus Jet Sources Options

[belleraphon1]

"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."

Craig

All... the news above from my post last year has bothered me since I first read it. However in slide 15 of this CASSINI team CHARM presentation, looks like CASSINI has found the sodium....
http://saturn.jpl.nasa.gov/multimedia/prod..._Cuzzi_Seal.pdf

"CDA in situ measurements show water, sodium, silicon in E ring grains, and even some metallic grains which may be on unusual orbits"

Can hardly wait for the team's update on data from the August flyby... and we have two more flyby's coming up next month!!! Wonder if they are hanging onto these results until after those encounters?

Very Cool!!!!

Craig

[marsbug]

I have a feeling they will wait to release the results, but I hope they don't!

[Vultur]

I have a feeling they will wait to release the results, but I hope they don't!

I hope not, too. I wonder how many icy moons in the Solar System will turn out to have subsurface oceans - Europa looks very promising, and now Enceladus...

[dvandorn]

...and according to some sources, Ganymede and even Callisto may have subsurface oceans, albeit not of the extent of Europa's.

-the other Doug

[ngunn]

Not forgetting Titan, where the solid ice crust has actually been observed floating around a bit relative to the interior - possibly the strongest evidence so far of an internal ocean anywhere. Other possibilities include Neptune's Triton and non-moon Pluto.

[tedstryk]

Speaking of the jets, check out this night side image - http://saturn.jpl.nasa.gov/multimedia/imag...ails168613.html

Here is a shorter exposure to go with it.... http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=168612

[vexgizmo]

I wonder how many icy moons in the Solar System will turn out to have subsurface oceans...

Maybe middle-sized moons, too, if they contain ammonia which acts like an antifreeze.
http://blog.wired.com/sterling/2008/09/involuted-ocean.html

[tasp]

Just curious if anyone knows if the R factor of snow increases or decreases if it is in vacuum. If a fluffy surface layer traps heat better than solid ice, and even better if it is vacu-foofed, maybe the internal energy source can be smaller and easier to explain.

[scalbers]

Speaking of the jets, check out this night side image - http://saturn.jpl.nasa.gov/multimedia/imag...ails168613.html

Here is a shorter exposure to go with it.... http://saturn.jpl.nasa.gov/multimedia/imag...iImageID=168612

Quite the images. Interesting that the plumes are visible without a super high phase angle (i.e. a fairly appreciable crescent noted). Comparison to the Saturnshine gives one a nice sense of the plumes' brightness.

[marsbug]

I know I'm being impatient, and I know that the cassini team have a lot of work to do, but, well I was wondering if it would be worth e-mailing the team and asking if they planned to hold onto the most recent flyby data until after the next two Enceladus flybys. It wouldn't surprise me if they did but, well, I'm just wondering whats happened to it?

[belleraphon1]

All..

found the following paper online
"The E-ring in the vicinity of Enceladus II. Probing the moon’s interior—The composition of E-ring particles"

"Abstract
The population of Saturn’s outermost tenuous E-ring is dominated by tiny water ice particles. Active volcanism on the moon Enceladus, embedded in the E-ring, has since late 2005 been known to be a major source of particles replenishing the ring. Therefore particles in the vicinity of Enceladus may provide crucial information about the dynamical and chemical processes occurring below the moon’s icy surface. Here we present a statistical evaluation of more than 2000 impact ionisation mass spectra of Saturn’s E-ring particles, with sizes predominantly below 1 μm, detected by the Cosmic Dust Analyser onboard the Cassini spacecraft. We focus on the identification of non-water features in spectra otherwise dominated by water ice signatures. Here we specify the categorisation of two different spectrum types, which probably represent two particle populations. Type I spectra imply pure water ice particles, whereas in Type II spectra organic compounds and/or silicate minerals are identified as impurities within the icy particles. This finding supports the hypothesis of a dynamic interaction of Enceladus’ rocky core with liquid water."
© 2007 Elsevier Inc. All rights reserved.

http://lasp.colorado.edu/~horanyi/FTP/Cass...-ring2_2007.pdf

This report details data from the 2005 Enceladus encounters.

From this, the sodium detection appears to be contamination from the detector but the silicate detection is firm.

Enjoy..

Craig

[marsbug]

They seem to have a good handle on the sodium contamination, would they not take it into account before claiming they had found sodium in the E-ring?

I've decided against badgering the Cassini team (the right and obvious decision but impatience skews my perception sometimes), I'm sure they've got enough on their plates.

[belleraphon1]

They seem to have a good handle on the sodium contamination, would they not take it into account before claiming they had found sodium in the E-ring?

Keep in mind that this report is from data acquired in 2005. The team may have gotten better data since then.

All be be revealed in due time, I am sure. These teams are no doubt very busy getting together presentations for the upcoming DPS.

Craig

[Juramike]

New article in Nature according to recent space.com article. Looks like there is evidence for a large body of salty water deep in Enceladus, but that the jets are fueled by slow evaporation deep underground.

The evidence for sodium salts is indirect, coming from E ring dust particles rather than Enceladus jets. (Quoi?)

So more like a humidifier in the corner rather than "Cold Faithful".

Now, evidence points precisely to such a salty body of water. The results come from data collected by the Cosmic Dust Analyzer instrument aboard Cassini, which showed sodium salts within ice grains of Saturn's E ring.

The composition of different sodium compounds and overall salt levels correspond with what the scientists would expect if there were an ocean beneath the moon's icy shell.

"If you have liquid water in contact with a rocky core, then salts would be the most abundant dissolved compounds," Postberg told SPACE.com. "The only way to get that much salt into water is to extract it from rock."

In another study published in the June 25 issue of Nature, researchers report results from ground-based observations of the vapor cloud in Saturn's E ring, rather than the ice grains. These observations didn't show any sodium in the vapor. The finding, however, doesn't exclude the possibility of an Enceladan ocean.

[Ron Hobbs]

In the Geophysical Research Abstracts, Postberg et al. claim to have found Na in the plumes.

Sodium Salts in Ice Grains from Enceladus' Plumes

This was picked up by the New Scientist, MSNBC and the BBC. (See my posts in the October 31 thread (I don't seem to be able to insert links correctly))

I would love to see a discussion of this finding is relation to the current news.