Tropical Lakes On Saturn Moon Could Expand Options For Life

ananyo writes "Nestling among the dunes in the dry equatorial region of Saturn's moon Titan is what appears to be a hydrocarbon lake. The observation, by NASA's Cassini spacecraft, suggests that oases of liquid methane — which might be a crucible for life — lie beneath the moon's surface. Besides Earth, Titan is the only object in the Solar System to circulate liquids in a cycle of rain and evaporation, although on Titan the process is driven by methane rather than water. This cycle is expected to form liquid bodies near the moon's poles, but not at its dune-covered equator. Now scientists think they have found a tropical lake — some 60 kilometers long and 40 kilometers wide, and at least 1 meter deep — in Cassini observations made between 2004 and 2008. Because tropical lakes on Titan should evaporate over a period of just a few thousand years, the researchers argue that these ponds and lakes are being replenished by subsurface oases of liquid methane. That would expand the number of places on the moon where life could potentially originate."

Helium rain

[arisvega]

Besides Earth, Titan is the only object in the Solar System to circulate liquids in a cycle of rain and evaporation

No, [latimes.com] it is not [space.com].

Re:Does it have to be pure methane?

[lixns21]

Plausible but unlikely. Plausible since remnants of methane tend to form complex organic compounds but unlikely since if the entire composition was a single compound, the spectrographic analysis would have likely identified it! And honey does dry out! http://scienceline.org/2007/04/ask-westly-crystallizedhoney/ [scienceline.org]

Re:Helium rain

[arth1]

What about Venus ? I thought it rained on Venus, hot sulphuric acid, but still..

Yes and no. It rains sulphuric acid in the upper athmosphere (which is almost all carbon dioxide and so dense you can almost swim in it), but the rain never hits the ground.

Still, Venus is - by far - the planet that resembles Earth the most. Much more so than Mars.
Yes, it's more inhospitable too.

Re:CHON is where it's at

[grep_rocks]

It takes more than just having the right elements to create life - water has some interesting chemical properties that methane lacks - such as it is one of the only chemicals which expands when it freezes, water is a polar molecule being slightly positive on one side and negative on the other, can form a large number of hydrogen bonds for its size, and especially relevant is that it is a fantastic solvent - all these properties are favorable for life, for example being a good solvent allows other molecules and ions to dissolve into water, allowing for lots of different types of chance chemical reactions to occur between different dissolved molecules - Methane is not as good a solvent as water, as it lacks polarity, however some people have proposed life working using poly-lipids as a substitute for proteins in non-polar liquids but because it is a poor solvent the chances of life working in a methane ocean seem less likely than water...