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."

Comments

CHON is where it's at

[Pfhorrest]

AFAIK there's nothing to say that methane-based life couldn't also use DNA. Methane is still carbon and hydrogen. All living organisms on Earth are composed primarily of carbon, hydrogen, oxygen, and nitrogen (CHON), and the general presumption looking for life elsewhere in the universe is that places with high concentrations of those elements is a good place to look, because we know life can be built out of them. Hydrogen and carbon dioxide are interconvertible with methane and water very much like carbohydrates (such as methane) and oxygen are interconvertible with carbon dioxide and water; all these processes involve the, C, H, and O of CHON equally, and the former was actually quite common early in the history of life on Earth. It wasn't until photosynthetic organisms started using light to convert CO2 and H20 into O2 and various CH's that the now-free O2 and CH4 reacted to become more of the H2O and CO2 that now cover our planet. (And then the O2 kept piling up and almost killed it all until some enterprising organisms started combusting it with those other CH's into more H20 and CO2).

TL:DR; methane really isn't all that weird an environment to find life much like we know it. Molten silicon and iron, on the other hand, or liquid helium, that would require some as-yet-unknown chemistry).