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NASA Space Science

Tropical Lakes On Saturn Moon Could Expand Options For Life 84

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."
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Tropical Lakes On Saturn Moon Could Expand Options For Life

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  • by wisebabo ( 638845 ) on Thursday June 14, 2012 @03:46AM (#40319955) Journal

    Absolutely positively evidence that the universe was crawling with life!

    It would mean life is not only not based on DNA (and thus couldn't be a result of cross-contamination with earth as has been suggested might be the case for any Maryian life we might come across), but wouldn't even be based on WATER! It would mean that perhaps anywhere there was a liquid at perhaps almost any temperature we should be on the lookout for life! (Liquid helium on Pluto? Molton magma in the earth's mantle?)

    I read in the book "Life as we do not know it" that Titan could be the home to up to three(!) completely separate "Domains" (the authors term) of life. Water based (around some heated cryo-volcanoes perhaps), ammonia-water, and methane based.

    Someday we'll send a manned mission to orbit Titan. Then using remote balloons(!) and boats(!) they'll be able to really investigate these possibilities. Until then, the time lag will make things difficult (but not impossible I hope).

  • by Pfhorrest ( 545131 ) on Thursday June 14, 2012 @04:26AM (#40320099) Homepage Journal

    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).

  • Rivers? (Score:4, Interesting)

    by MichaelSmith ( 789609 ) on Thursday June 14, 2012 @04:34AM (#40320131) Homepage Journal

    Maybe liquid methane flows from the poles to the equator and evaporates there. Then gaseous methane flows to the pole through the atmosphere and precipitates out.

  • by Viol8 ( 599362 ) on Thursday June 14, 2012 @06:29AM (#40320599) Homepage

    We know on earth deserts can form in a few thousand years so why not on Titan? Perhaps that lake is the remenant of something much larger that formed when that part of the moon was far wetter a few thousand years ago?

  • by myowntrueself ( 607117 ) on Thursday June 14, 2012 @11:15AM (#40322907)

    One of the things that contributes to 'life as we know it' is the lipid bi-layer which forms cell membranes.

    The lipid bi-layer is formed by molecules one end of which is hydrophobic and the other end of which is hydrophilic.

    One has to wonder if similar analogous molecules exist for methane instead of water? Ie methane-phobic on one end and methane-philic on the other.


  • Re:Helium rain (Score:4, Interesting)

    by ShanghaiBill ( 739463 ) on Thursday June 14, 2012 @11:30AM (#40323095)

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

    The surface of Venus is inhospitable. But people could live in the atmosphere. The atmosphere of Venus is so dense, that a floating city filled with an Earth-like atmosphere of oxygen+nitrogen would have enough buoyancy to float. The upper atmosphere is much cooler than the surface. Sunlight is more than twice as bright as on Earth, so there would be plenty of energy.

  • by ceoyoyo ( 59147 ) on Thursday June 14, 2012 @02:58PM (#40326505)

    On Titan you're surrounded by combustable fuel, but you have to go looking for oxidizer. On Earth, we're surrounded by oxidizer but have to go looking for fuel. As far as fire is concerned, it's the same thing.

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