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NASA Science

Craters Quickly Hidden On Titan 39

MightyMartian writes "NASA scientists say Cassini has discovered that far fewer craters are visible on Titan than on the other moons of Saturn. The craters they have discovered are far shallower than other moons' craters and appear to be filling with hydrocarbon sand. On top of being another reason Titan's active geology is very cool, it adds to the mystery of where all the methane on Titan is coming from. 'The rain that falls from Titan's skies is not water, but contains liquid methane and ethane, compounds that are gases at Earth's temperatures. ... The source of Titan's methane remains a mystery because methane in the atmosphere is broken down over relatively short time scales by sunlight. Fragments of methane molecules then recombine into more complex hydrocarbons in the upper atmosphere, forming a thick, orange smog that hides the surface from view. Some of the larger particles eventually rain out onto the surface, where they appear to get bound together to form the sand.'"
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Craters Quickly Hidden On Titan

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  • cool

    About 90 kelvins, right? Its only twice as cold as the coldest place on Earth, relative to normal Earth temperatures.

    • The source of Titan's methane remains a mystery because methane in the atmosphere is broken down over relatively short time scales by sunlight

      Hang on a minute: wasn't free methane being used as an indicator of life on Mars? So where does this methane come from?

      • by Anonymous Coward

        Cows produce methane. Isn't it obvious?

        • Cows produces methane on earth.

          But cows can't survive on Titan's climate.

          There must be a lot of "something" on Titan that are producing the massive amount of methane.

          They could be nano-cows.

          • http://fc00.deviantart.net/fs71/f/2012/056/e/e/space_cows_by_jessicabane501-d4qxz3i.jpg [deviantart.net]

            You just can't trust those cows. I mean, cows have people trained in India to starve before they will consider eating a cow. Cows are smarter than we give them credit for.

            • Re: (Score:3, Informative)

              by Anonymous Coward
              Actually the Bhagavad Gita allows an exception to killing in the face of starvation. A human being can sustain themselves without killing. Because life is sacred (crazy thought), an enlightened person should choose not to kill over killing. Because cows make milk and many dishes can be made from milk without killing, and mother's produce milk, cows are considered sacred. However, if you are faced with starvation, self-preservation is allowed. As religion goes, it's not quite as crazy as a god that depe
          • by lennier ( 44736 )

            Cows produces methane on earth.

            But cows can't survive on Titan's climate.

            There must be a lot of "something" on Titan that are producing the massive amount of methane.

            Spherical cows, obviously.

      • by ThePeices ( 635180 ) on Sunday January 20, 2013 @04:18AM (#42637987)

        The source of Titan's methane remains a mystery because methane in the atmosphere is broken down over relatively short time scales by sunlight

        Hang on a minute: wasn't free methane being used as an indicator of life on Mars? So where does this methane come from?

        Kind of. Methane could be generated on Mars either by biological means, or by geological means.

        If its geological, then the sub-surface of Mars is more active than we thought.
        If its biological in origin, well there's the biggest discovery in human history right there.

        For the record, im guessing geological.

      • So where does this methane come from?

        Sorry, that was me.

      • Re: (Score:2, Informative)

        by Anonymous Coward
        On Mars, it is expected that methane would be destroyed pretty quickly due to photochemistry, and in order for th current, low concentrations to maintain a steady state, there has to be a source somewhere. Titan would be a difference case, as it receives less sun light, may have started with a much larger source of methane. It wouldn't take as large of an ongoing source of methane to result in the levels we see on Titan, as opposed on Mars.
    • If you go, don't forget your mittens!
  • Maybe the source of the methane is some exotic life form: They feed on the more complex hydrocarbons and reduce them to methane (I'm no chemist, so I don't really know whether this would be a possible way to gain energy). They cannot consume the methane to gain more energy because they are lacking oxygen, therefore the methane is the end product, just like CO2 for earth's life. The methane then goes into the atmosphere where it gets combined into more complex hydrocarbons using solar energy (that process is

    • Re:Wild theory (Score:5, Insightful)

      by MichaelSmith ( 789609 ) on Sunday January 20, 2013 @04:29AM (#42638005) Homepage Journal

      Yeah its interesting but it should be possible to calculate the amount of biomass required to do that. There is a hell of a lot of methane in this cycle on Titan which implies a lot of life. My guess is that the stuff would have to blanket the planet and it would need a fast metabolism. For me that means it must be in a subsurface ocean. The surface is too cold for a high energy metabolism.

      • They must be eating a lot of cheese.

          I get that too:)

      • it should be possible to calculate the amount of biomass required to do that. There is a hell of a lot of methane in this cycle on Titan which implies a lot of life.

        IF and only IF the source of the methane is biological. Which is not necessarily the case.

        The OP is implying a carbon cycle where, in effect, the sunlight alters (increases) the amount of net bond energy per carbon atom, by converting methane vapour into "higher" hydrocarbons ; then at the surface the metabolism of the (putative) organisms rev

  • by Hadlock ( 143607 ) on Sunday January 20, 2013 @04:20AM (#42637991) Homepage Journal

    Wouldn't Titan's ultra-dense atmosphere have something to do with this? Most meteors come in at a high angle of incidence, meaning they graze the atmosphere, then fall in as they're slowed down to a capture speed.
     
    Titan's atmosphere is something like what, three times as dense as Earth's atmosphere? It's up there with Venus, not Mars or Io, so shouldn't we be comparing it to planets, not moons? Keep in mind that visually, Titan is only about 8% smaller than Mars, and quite a bit larger than Earth's moon.

  • by Mister Liberty ( 769145 ) on Sunday January 20, 2013 @06:12AM (#42638221)

    stays mainly in the crater.

  • It must be all the frozen Ewoks: http://youtu.be/5r_TlPwZOvU [youtu.be]
  • by PPH ( 736903 ) on Sunday January 20, 2013 @12:20PM (#42640055)

    ... Beijing.

The world is not octal despite DEC.

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