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Posted by: volcanopele Jun 28 2005, 05:36 PM

The Rev09 Titan observations have been released with much fanfare (which of course caused the delay in release...)

Clouds in the Distance
http://ciclops.org/view.php?id=1162

Land of Lakes?
http://ciclops.org/view.php?id=1161

And my obligatory blog posting
http://volcanopele.blogspot.com/2005/06/lake-on-titan.html

Posted by: Phil Stooke Jun 28 2005, 05:56 PM

It took me quite a while to match last July's images with these new ones. But here is the same area from July '04 (bottom of message):

(bear in mind this is my crummy image processing, not VP's good stuff)

The 'lake' is the dark spot at upper left in my image. So it was also there a year ago... and looks like it had a little cloud beside it. Lots of other things match too, so no sign anything changes. When I was having trouble matching things before I deluded myself into thinking surface changes were to blame.

Phil

Posted by: JRehling Jun 28 2005, 07:46 PM

Look above the south pole and to the right of the peanut. There's an area of light-on-dark which is almost shaped like an asterix (*). The shape there and near the south pole are very reminiscent of the Huygens "landing strip" area. I think we're looking at an area with a tectonic past and a rainy/drainy present.

If there are seasonal icecaps, they apparently aren't plowing the relief here into the ground under crushing weight.

Posted by: Decepticon Jun 29 2005, 01:47 AM

http://www.planetary.org/news/2005/titan_lake_0628.html





VP will there be any full global processed images from Rev09 in the upcoming week?

Once again amazing work.

Posted by: edstrick Jun 29 2005, 02:07 AM

I've bandpass filtered the tif version of one of the "land of lakes" images to bring out all available local detail in the image. Of course, all surface detail poo's out in the lower 3'rd of the image especially toward the corners where low sun angles and longer viewing paths fog surface detail to nothing. The clouds, at higher altitude, show sharp detail where the surface smudges to almost nothing.

Some of the smaller "lake-oids" have fairly uniform dark surfaces with sharp edges, others seem to have areas that are considerably lighter. Edge sharpness of the features seems to vary, but many high contrast edges are sharp down to the noise limited resolution of the image. One darkish area well above and a bit to the right of center has a lot of internal structure, some of it vaguely left-right as though part of a fracture pattern and gives an impression of a "marsh-oid" instead of lake like feature.

"Curiouser and Curiouser", said Alice.

Posted by: tty Jun 29 2005, 06:02 PM

Here on Earth glaciers don't "plow relief into the ground". They will cause a broad regional depression of the glaciated area and a "forebulge" outside it, but this hardly affects relative relief.
What does affect relief is the movement of warm-based glaciers over ground which grinds away the surface and when channelled will cause dramatic relief (fiords). This takes a long time though, seasonal glaciers would probably not have time to move very much. Also they might well be cold-based, i e frozen to the substrate. In such glaciers the movement mostly occurs within the ice and there is very limited erosion of the substrate. Warm-based glaciers have a water film between the ice and the substrate which "lubricates" them. The erosive power is further increased if there is a considerable amount of rocky material (moraine) in the ice. I have no idea whether a methane glacier on Titan would be warm- or cold-based, nor if water-ice under Titanian conditions is harder than solid methane and would function as morainic material.

tty

Posted by: scalbers Jun 29 2005, 09:23 PM

I also see what looks like the peanut lake in the Cassini (a.k.a. VP) map of Titan from earlier this
spring. Note at this URL - http://photojournal.jpl.nasa.gov/jpeg/PIA06219.jpg. It can be seen
at about 75 degrees S latitude and 180 longitude. This shows up pretty clearly when rendered
in a polar view.

Posted by: volcanopele Jun 30 2005, 05:44 PM

BTW, pay careful attention to the movie and watch the clouds...

Posted by: JRehling Jun 30 2005, 06:23 PM

The first thing I noticed was that we're seeing different windspeeds at different altitudes. It looks as though the main body of clouds is rising up from a relatively still low level, then being blown clockwise around the pole when reaching some higher altitude. Interestingly, a small puff to the west seems to be blowing in the opposite direction -- it is hundreds of km away, so it's not inexplicable, but it means that there's something more than a simple radial motion along the parallels.

I also rewatched the four-frame movie I made of Ta clouds. Something similar is in evidence. White "nuggets" remain in the same place in all four frames but each starts to extend downwind in successive frames.

Seeing the Rev09 movie alone, I might suspect that a volcano or geyser field was the source of a plume. But the Ta movie shows a very broad area of origin, which makes an endogenous origin seem less likely. Also, the ring of southern cloud presence is very suggestive of the dark ring seen in the haze around the northern hemisphere in Voyager images, and it's hard to believe that volcanos are seasonal if they are the product of mantle upwelling. On the other hand, if subtle changes in temperature can wring a liquifier from the crust... maybe the distinction between volcanos/lava on the one hand and lakes/evaporation is a distinction that can be blurred. A "geo"/endogenous explanation would make the here-now/gone-tomorrow nature of the clouds easy to explain, although meterology can play the same trick (as I notice in the San Francisco summer, when weeks of sun can suddenly be interrupted by an all-blotting fogbank).

I'm not sure if I've come close to the significant thing that has Jason clearing his throat at us to notice... By and large, it looks to me like a vertical updraft in the cloud region has led to condensation at some altitude (probably about the altitude where Huygens saw an increase in methane), and then the newly-condensed clouds continue to rise until they get horizontal winds, and blow downrange until dissipated. This could be an interesting, but not a "WOW!!!" meteorological system, as far as I've discerned. But I may be missing something...

Posted by: alexiton Jul 1 2005, 09:34 AM

Howdy Huygenauts,

forgive my naive opinion but in places actually looks like topography might be penetrating the haze layer. Especially top/left where it looks somewhat like something is ebbing over the prominent bits(hilights) in the GIF animation. Also, the correspondence of hilights against darker tones is suspiciously harmonious in places, like the way the bottom centre ovoidal bright patch modulates inline with the apparent contours of the underlying(darker) form (bad quantization?). Of course could just be some lenticular thingy, and other bits definately look to be scooting by in a cloudlike fahion, but foresaking the tendency of clouds to be tied to things geographically does look curiously uncloudlike in places...

Posted by: Decepticon Jul 1 2005, 09:48 AM

When I look at the animation it seems to be coming from the surface.

Surface venting? Similar to Triton Geysers.