[X] My Assistant

[Palomar]

Best evidence yet

*...for a shoreline on Titan; they're calling it "dramatic." Area measures 1,060 by 106 miles. Is from Cassini radar, obtained during the latest flyby. Speculation continues regarding seepage of liquid from the ground/ground springs and/or rainfall.

[exoplanet]

Has anyone put forward a theory that some sort of chemical interaction may be taking place when liquid methane on the surface of Titan comes into contact with the complex hydrocarbons raining down from the atmosphere. Perhaps there is some sort of organic opaque film forming on top of liquid methane and this may be the reason Cassini cannot see the specular glints from the oceans and lakes.

I posted this idea because I really am having a hard time grasping that the dark deposits are dried up mud flats from particulates being washed from the high surface into the low areas. If this would be the case - the dark particulates would be seen only in the dried up playas and intermittently filled streambeds. These dark particulates are also seen in the short channels that are most likely caused by powerful springs that are presumably still active. These channels should be light colored at the bottom and not dark due to the constant running of the methane springs.

Also, The ice pebbles surrounding the lander were very rounded, light colored and clean (without a crust of dark hydrocarbon mud) which leads me to believe that they have been eroded by liquid (wave or streambed action) very recently.

[The Messenger]

...
I posted this idea because I really am having a hard time grasping that the dark deposits are dried up mud flats from particulates being washed from the high surface into the low areas.  If this would be the case - the dark particulates would be seen only in the dried up playas and intermittently filled streambeds.  These dark particulates are also seen in the short channels that are most likely caused by powerful springs that are presumably still active.  These channels should be light colored at the bottom and not dark due to the constant running of the methane springs. 

Also, The ice pebbles surrounding the lander were very rounded, light colored and clean (without a crust of dark hydrocarbon mud) which leads me to believe that they have been eroded by liquid (wave or streambed action) very recently.

Agreed. I would expect to see chromographic banding, if dark organics are being washed by any solvent process - reverse phase or otherwise. I don't see any evidence of this.

In the Great Basin of Utah/Nevada, the "bathtub ring" caused by a lake that dried up 10-20,000 years ago is very apparent in either radar or visual imaging. In southern Utah, the millenial old uplifted ocean bed responsible for Zion, Arches, and Canyonlands national parks demonstrate little if any of the shoreline evidence obvious in 'geologically current' features.

Since the surface of Titan is relatively new, if we cannot find evidence of shoreline erosion, we should expect to find tetonic and volcanic activity.

[imran]

Just an article I found interesting.

Rivers on Titan, one of Saturn's moons, resemble those on earth

[Guest_Richard Trigaux_*]

Just an article I found interesting.

Rivers on Titan, one of Saturn's moons, resemble those on earth

I do not think that what we see on Huygens images really ressemble river beds. It is slightly different, and these differences are revealing of the conditions which created them.

If you look at river beds in temperate countries like Europe of USA (desert excepted) you see very narrow channels which would be invisible on Huygens images (assuming a replica of Huygens photographied them in the same conditions). What we see on Huygens images is hundred times wider, and rather looks like what we see in deserts like Sahara (I flew over in in aircraft, it is really visible).

This is because, in temperate climate, there is a weak but constant rain fall, which creates narrow channels, but neatly cut, what we call river beds. In deserts, there are rather large surges of rain in an however dry climate, and this does not create river beds, it creates large flow traces occupying all the valley bottom, or large alluvial fans. Sahara water traces can be several kilometre wide, in places where there is no river bed.

So we can conclude that Titan has rather rare rains, but very intense when they come. And, for some reason, these precipitations mark their passage in dark, likely some kind of tar formed by the organic materials falling from the atmosphere.

[JRehling]

I do not think that what we see on Huygens images really ressemble river beds. It is slightly different, and these differences are revealing of the conditions which created them.

If you look at river beds in temperate countries like Europe of USA (desert excepted) you see very narrow channels which would be invisible on Huygens images (assuming a replica of Huygens photographied them in the same conditions). What we see on Huygens images is hundred times wider, and rather looks like what we see in deserts like Sahara (I flew over in in aircraft, it is really visible).

I think in most temperate places in Europe/USA, if you removed all plants first, and avoided areas where humans have reworked streams into artificial irrigation systems, you would see streams rather densely populating the landscape for a Huygens-like eye to perceive.