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Posted by: SigurRosFan Oct 20 2005, 05:50 PM

Cracks Or Cryovolcanoes? Surface Geology Creates Clouds On Titan

http://www.spacedaily.com/news/saturn-titan-05zd.html

Posted by: OWW Oct 21 2005, 08:06 AM

I love it how the next day, other scientists already have a theory that contradicts the first one:

http://uanews.org/cgi-bin/WebObjects/UANews.woa/7/wa/MainStoryDetails?ArticleID=11870

"Griffith argues that it's improbable that many ice volcanoes, all aligned at 40 degrees south latitude, are forming these clouds"

Posted by: mike Oct 21 2005, 07:21 PM

Different people don't always agree on things.

Posted by: Rob Pinnegar Oct 21 2005, 07:36 PM

Especially at this stage of the game. Titan is a complicated place and we still haven't seen large parts of it in much detail yet. Imagine trying to figure out Earth from one lander and an orbiter taking fuzzy pictures. Even without the biosphere it'd be a big job -- plate tectonics, thunderstorms, hurricanes, contintental glaciation, ocean currents, erosion, rivers...

Is Titan just as complex? I hope so, personally.

Posted by: volcanopele Oct 24 2005, 08:16 PM

I agree with the VIMS group on this one. I just can't see how a line of volcanoes or cracks right at this latitude across thousands of miles could exist. Most likely we are looking at convection driven by general circulation.

WRT the Roe et al. paper, I don't think the question is why the clouds preferentially form near 0 and 90 degrees west, but why the DON'T seem to form as often at other locations along 40 degrees south.

Posted by: Bob Shaw Oct 24 2005, 09:56 PM

Welllll... ...you get volcanoes on Earth in lines and arcs, and on Mars - and who'd have believed in Valles Marineris, or the East African Rift Valley? So you *can* get large structures associated with vulcanism her, so why not on Titan?

Bob Shaw

Posted by: BruceMoomaw Oct 25 2005, 03:34 AM

The team seems in little doubt that the LATITUDE of the 40 deg S. clouds is determined by Titan's Hadley convection cycles. The question remaining is why they seem to congregate around 0 deg LONGITUDE, and the only plausible explanations for that involve surface phenomena (whether it's geothermal vents of methane vapor, or high mountains over which Titan's winds are blowing).

Posted by: remcook Oct 25 2005, 12:42 PM

...but like they say: the fact that the clouds don't appear at exactly the same spot every time is an indication that mountains may not be the cause...

Posted by: volcanopele Oct 25 2005, 05:55 PM

Yes, but two such features, right on the same latitude line, but no where else, and without apparent surface expression seen by either ISS or RADAR? While I would love to see a line of volcanoes or a rift zone, I just don't think the evidence fits. Now, I do agree that volcanic activity is pumping methane into the atmosphere, but I think these geysers are likely more evenly spaced or at least not coincidently on a line of latitude. So Hadley Circulation is likely the cause of their formation location with either a selection effect or something preventing the clouds from forming in other locations is the likely culprits for the supposed clustering at certain longitudes.