Hydrocarbon Rain Swells Titan's Lakes

Rob Carr writes "According to the Cassini team, 'Recent images of Titan from NASA's Cassini spacecraft affirm the presence of lakes of liquid hydrocarbons by capturing changes in the lakes brought on by rainfall.' The northern lakes are now larger following a period in which hydrocarbon clouds covered their skies. (The research was published in the journal Geophysical Research Letters.) This change adds to the evidence these areas are indeed hydrocarbon lakes. But this discovery raises several more questions: where is the methane in the atmosphere coming from, and how long can this complex hydrocarbon cycle on Titan go on? The new evidence emphasizes the need for another mission to Titan."

Comments

Re:Another "planet" with resources...

[Anonymous Coward]

You must be a nut to think that "Dubya" will be a single, isolated incident in the history of mankind.

Obvious source of the methane...

[jimbudncl]

Uranus.

source http://www.esa.int

[Saysys]

The question of how much liquid is on the surface is an important one because methane is a strong greenhouse gas on Titan as well as on Earth, but there is much more of it on Titan. If all the observed liquid on Titan is methane, it would only last a few million years, because as methane escapes into Titan's atmosphere, it breaks down and escapes into space.

If the methane were to run out, Titan could become much colder. Scientists believe that methane might be supplied to the atmosphere by venting from the interior in cryovolcanic eruptions. If so, the amount of methane, and the temperature on Titan, may have fluctuated dramatically in Titan's past.

Re:source http://www.esa.int

[Cally]

I actually shelled out $9 to read the Geophysical Review Letters paper (I take my armchair planetary science geekery pretty seriously, but sadly not enough to justify journal subscriptions.) One possibility mentioned is sub-surface reservoirs as a possible source keeping the atmosphere topped up. (Note that unlike on earth, where methane has an atmospheric lifetime measured in weeks, at Titan it's millions or tens of millions of years.) Another interesting thing is the description of GCMs (global circulation models) and evidence of classical, earth-style Hadley cells, a major feature of earth's climate.