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Selfsim
2013-Jun-13, 01:19 AM
Didn't notice this when it came up (April 15) ...

Titan's Methane World -- Not Built to Last? (http://saturn.jpl.nasa.gov/news/cassiniscienceleague/science20130412/)


"We are seeing an active Titan whose active chemistry may come to an end in some tens of million years," said JPL scientist Christophe Sotin, who has been analyzing Cassini measurements of Titan's lakes and seas. Titan, it appears, will eventually run out of methane.
..
Titan's methane, it turns out, is not being replaced fast enough to sustain the methane cycle, according to the new model Sotin and his colleagues have published.
There's lots of interesting ideas coming from the study of the lakes, (mostly ethane), but if the methane is going to disappear .. then the beloved speculated "methanogens" had better be adaptable, too!?!

However, another interesting snippet is right at the bottom:


The Question of a Titan Ocean Gets More Complicated:
The strong correlation between small lakes seen by Titan radar and similar small dark patches seen by VIMS supports recent radar observations that question whether Titan's rotation is non-synchronous. If Titan's rotation is synchronous, it could complicate theories that argue for a global subsurface ocean on Titan that decouples the moon's outer ice shell from the inner core.Just goes to show how the numbers of speculative hypotheses about Titan, is inversely proportional to the paucity of the data. (Which is increasing over time, courtesy of Cassini).

Colin Robinson
2013-Jun-13, 05:34 AM
Didn't notice this when it came up (April 15) ...

Titan's Methane World -- Not Built to Last? (http://saturn.jpl.nasa.gov/news/cassiniscienceleague/science20130412/)


There's lots of interesting ideas coming from the study of the lakes, (mostly ethane), but if the methane is going to disappear .. then the beloved speculated "methanogens" had better be adaptable, too!?!

It looks like they still have time to do some partying.


However, another interesting snippet is right at the bottom:

Just goes to show how the numbers of speculative hypotheses about Titan, is inversely proportional to the paucity of the data. (Which is increasing over time, courtesy of Cassini).

It's like a jigsaw puzzle where more and more pieces are available, just not quite enough to be sure how they all fit together or how the big picture is going to look.

Colin Robinson
2013-Sep-19, 04:34 AM
Recent study of data from Cassini's VIMS instrument (http://www.universetoday.com/104770/ice-volcanoes-likely-alter-titans-surface-brightness-study/)

reports changes in Titan's surface brightness consistent with active volcanic activity. Volcanic activity would tend to replenish the hydrogen/methane content of the atmosphere, implying that Titan's current chemically active atmosphere may not be a transient anomaly after all. If there are organisms which thrive on the current atmosphere, this is good news for them.

Selfsim
2013-Sep-19, 11:10 PM
Recent study of data from Cassini's VIMS instrument (http://www.universetoday.com/104770/ice-volcanoes-likely-alter-titans-surface-brightness-study/)

reports changes in Titan's surface brightness consistent with active volcanic activity. Volcanic activity would tend to replenish the hydrogen/methane content of the atmosphere, implying that Titan's current chemically active atmosphere may not be a transient anomaly after all. If there are organisms which thrive on the current atmosphere, this is good news for them.Hmm .. I have a feeling that this article might be a counter to this one (http://phys.org/news/2013-08-cassini-titan-rigid-weathered-ice.html)(?):

The researchers calculated that, in this model, Titan's ice shell would have to have a rigid layer at least 40 kilometers thick. They also found that hundreds of meters of surface erosion and deposition are needed to account for the observed imbalance between the large roots and small surface topography. The results from their model are similar to estimates obtained by geomorphologists studying the erosion of impact craters and other features on Titan.

These findings have several implications. For example, a thick rigid ice shell makes it very difficult to produce ice volcanoes, which some have proposed to explain certain features seen on the surface

Unlike Earth's geologically active crust, Titan's ice shell isn't getting recycled by convection or plate tectonics. "It's just sitting there, and weather and erosion are acting on it, moving stuff around and redepositing sediments," Nimmo said. "It may be like the surface of Earth would be if you turned plate tectonics off."Both reports make use of the latest Cassini data, yet there seems to be some disagreement in the conclusions formed(?)..

Colin Robinson
2013-Sep-20, 12:26 AM
Hmm .. I have a feeling that this article might be a counter to this one (http://phys.org/news/2013-08-cassini-titan-rigid-weathered-ice.html)(?):
Both reports make use of the latest Cassini data, yet there seems to be some disagreement in the conclusions formed(?)..

Interesting point. These two reports both use recent data from Cassini, but they use different sorts of data.

One is based on a study of visual and infrared brightness of surface features, the other on measurements of variations in Titan's gravitational field. One reports changes in surface brightness consistent with ice volcanos, the other reports lower-than-expected gravity in mountainous regions, consistent with iceberg-like structures in a thick rigid crust.

Maybe there are other explanations for the lower-than-expected gravity associated with Titan's mountains. E.g. What if they contain minerals which have low density due to bubbles — like pumice here on Earth? I'm not suggesting they would be made of the same compounds as pumice, just that they would have a comparable structure, and a comparable origin — volcanic activity and outgassing.