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The Cassini team has released the images from the most recent SAR pass over Titan, and it shows evidence of lakes of methane in the region near the north pole. They would be the first bodies of liquid found on the surface of a planet other than Earth. Very exciting stuff. The north pole is currently in the middle of a long, dark winter. Current speculation is that the poles get cool enough for methane to condense and fall as rain. In the new radar swaths, there are more lakes at higher latitudes. The Planetary Society has a good article about this:

http://planetary.org/news/2006/0724_Cas ... an_At.html

And the caption from JPL:

http://photojournal.jpl.nasa.gov/catalog/PIA08630

There's no global ocean of methane on Titan, but note how big some of those lakes are. One of them is at least 75km across.

--Chris

This is a very exciting find. If it pans out, I wonder what this might do for the possibility of methanogene biota?

Yes, I'm being extremely optomistic here....

Quite an interesting discovery indeed...
May it be the occasion to create a seasonal map for Titan?

That's a really interesting discovery. If these are actually lakes and not some weird geological feature no-one's thought of yet, it'd be interesting to search the south polar region for dry lake beds.

Heh, a global ocean would have been annoying in a way. Then we would have to send a second probe to map the ocean floor...

What kind of data do you need to be sure that they are lakes?

chaos syndrome wrote:That's a really interesting discovery. If these are actually lakes and not some weird geological feature no-one's thought of yet, it'd be interesting to search the south polar region for dry lake beds.

Heh, a global ocean would have been annoying in a way. Then we would have to send a second probe to map the ocean floor...

But we can't taste and smell the liquid on that....
Methane...not Cola....

ElChristou wrote:8O Quite an interesting discovery indeed...
May it be the occasion to create a seasonal map for Titan?

Oh I just can't resist the urge here (off topic alert)... Seasonal textures, I know I've said it many times on this forum, but repetitious texture changes, can we get them? I would love the ability to have textures repeat every x seconds or days or even fractions of a year in a cyclical nature.

buggs_moran wrote:

ElChristou wrote:8O Quite an interesting discovery indeed...
May it be the occasion to create a seasonal map for Titan?

Oh I just can't resist the urge here (off topic alert)... Seasonal textures, I know I've said it many times on this forum, but repetitious texture changes, can we get them? I would love the ability to have textures repeat every x seconds or days or even fractions of a year in a cyclical nature.

I'm thinking Blue Marble 2 ...

Personally I'm not convinced that they are definitely lakes, I think the Cassini Team has a bit too much wishful thinking when it comes to finding liquid on Titan. But I'm open to the possibility that they might be lakes, it'd take more convincing data to er, convince me more though .

Have a look at the radar swatch from the Oct 9th Titan flyby. It contains what I think are the most spectacular lakes we've seen so far on Titan:

http://photojournal.jpl.nasa.gov/catalog/PIA01943

--Chris

Hm. Crinkly bits, eh?

Those structures could have been formed by liquid, sure. As to whether there's lakes there right now, I'm still not convinced. I dare say that I see something like visibly shifting shorelines over different orbits, "lake" size changes due to seasonal variations, or wave structures or things like that, I won't be convinced...

Even larger lakes on Titan. This SAR swath from Cassini's 22 Feb 2007 Titan flyby shows a large lake with an island:



The island is about 90x150 km. It could in fact be a peninsula if the area to the right of the island isn't completely flooded. Some features are visible within the lake; whether or not these are above or below the lake surface depends on how deeply the radar signal penetrates into liquid methane (and how pure the liquid filling the lakes is.)

Here's more information on the SAR image: http://photojournal.jpl.nasa.gov/catalog/PIA09180

More recent evidence for lakes comes from the Cassini imaging team:

http://ciclops.org/view.php?id=2607

The pictures show a dark feature that could be a lake the size of the Caspian Sea. This is not the same lake as in the SAR image.

What'd I love to see is a specular texture for Titan with all the suspected lakes marked on it. This would be useful for figuring out when and where specular highlights from the lakes might be visible. It was pointed out that sunlight reflected from lakes in the polar regions may be attenuated enough by Titan's atmosphere so as to be undetectable, but I still think that creating a specular map would be a worthwhile project.

--Chris