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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."

13 of 110 comments (clear)

  1. inb4... by Anonymous Coward · · Score: 4, Funny

    inb4 people suggesting that we transport hydrocarbons from Titan to use as fuels on earth.

  2. Another "planet" with resources... by Anonymous Coward · · Score: 4, Funny

    ...to wage war over. It'll happen.

    1. Re:Another "planet" with resources... by Anonymous Coward · · Score: 5, Insightful

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

  3. Now all we need... by MichaelSmith · · Score: 4, Funny

    ...is fossil oxygen in liquid form reachable by drilling.

  4. Obvious source of the methane... by jimbudncl · · Score: 5, Funny

    Uranus.

  5. Nothing New ! by AmigaMMC · · Score: 4, Interesting

    I had already read that in Stephen Baxter's novel "Titan" - That guy is always so right! :)

  6. source http://www.esa.int by Saysys · · Score: 5, Interesting

    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.

    1. Re:source http://www.esa.int by Cally · · Score: 5, Informative

      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.

      --
      "None are more hopelessly enslaved than those who falsely believe they are free." -- Goethe
    2. Re:source http://www.esa.int by deglr6328 · · Score: 4, Informative

      jeez dude, you should really search, uhmmm this thing called the interwebs before letting yourself get raped by the ABSURDLY high prices these journals demand for a single paper! look. here. FREE! If you're an American YOU ALREADY PAID FOR THIS research. that's why it's on a NASA site for free. even when it isn't taxpayer funded research it's still VERY common to see a paper from a peer reviewed journal also up on a professor's personal page as a preprint or whatever.

      --
      - "Hear that?! The percolations are imminent! Cease your ingress!"
    3. Re:source http://www.esa.int by wizardforce · · Score: 4, Informative

      A few points of contention:
      1) methane is not an ideal gas at the average temperature of Titan.
      2) your velocity is root mean square not the velocity of all methane molecules in the atmosphere. The velocity of gas molecules is that of a bell curve not a concrete quantized single quantity. The fact is that although small by comparison, there's going to be a few methane molecules that have the velocity required to escape Titan's gravity no matter what the temperature. Granted the number of methane molecules capable of escaping increases dramatically with temperature... there should be enough that can escape to make millions or billions of years a fair approximation as to the average length of time a methane molecule stays bound in Titan's gravity well. THis is of course neglecting ionization of methane molecules caused by external radiation sources which reduce the lifetime of methane molecules captured.

      --
      Sigs are too short to say anything truly profound so read the above post instead.
  7. Re:bad modding by Slur · · Score: 4, Funny

    It will probably be the element that enables FTL.

    Imagination?

    --
    -- thinkyhead software and media
  8. Re:Wouldn't it be crazy... by NeverVotedBush · · Score: 4, Funny

    At least we would never have to worry about being invaded. A flamethrower would be the ultimate weapon against them in our atmosphere.

  9. Re:Wouldn't it be crazy... by az-saguaro · · Score: 4, Informative

    The reason that Titan is of such great interest (aside form the fact that Cassini-Huygens is giving us reams of data that we could never see from Earth), is that its chemistry is considered comparable to Earth in the pre-biotic eras. Our current hydro-nitrox environment evolved slowly due to abiotic and biotic chemistry starting with something that may be similar to what Titan now has. Somewhere in the distant past, biotic chemistry had to start in something that had high methane or other hydrocarbons. Even now, earth has extremophile niche organisms, some of which might well survive conditions comparable to Titan, to a degree.

    But, there are crucial differences. Biotic chemistry and the formation and evolution of life depend on complex molecules interacting in a solution. The ionic or soluble molecules, with nitrogen, oxygen, and sulfur, as well as C-H, which define life as we understand it, need water as the solvent. On Titan, it may exist at some thermal boundary far below the surface, but not at the top (the same reason that Jupiter's Europa, which does have water and ionic solutions in oceans near the surface is of such great interest as to the possibility of life).

    Titan is probably too cold to permit evolution. Atmospheric ionizations, lightening, deep geothermal chemistry, and so on may indeed have generated some biotic precursors - complex organics, amino acids, carbohydrates, or nucleic acids - but the chances of them being able to interact the gazillions of times needed to randomly find stable and regenerative molecules is unlikely at its ambient temperatures.

    However, the possibility that, at the right temperatures and thermodynamics, that these molecules could assemble and evolve in a methane solvent, is not beyond theoretical possibility, as long as enough nitrogen, oxygen, other atoms, (water), and energy are there to evolve the complexity of the molecules. This is what is presumed to have happened on earth.

    It is possible that current Titanic atmospheric chemistry is converting CH4 into larger hydrocarbons and other molecules, which would sequester the methane, making it "disappear". Since these molecules would be denser than methane, they might be below the observable surface, and we would not know about them. It is possible though that far enough below, where warmer, that the chemistry has become very complex, possibly pre-biotic, or perhaps even biotic. Of course, that is the point of this original article, that the hydrocarbons are there in mass quantities, so some sort of long term chemistry is going on.

    It would be interesting to take Titan's chemistry, as we have learned about it from Cassini-Huygens, put it in a laboratory bioreactor, adds some "lightening", heat, and so forth, and see what happens. In an old original Outer Limits episode from the 60's, they did just that, and some spooky creature evolved - how prescient!