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A New Angle on Martian Methane

dusty writes "A recent hypothesis paper entititled 'Martian CH4: Sources, Flux, and Detection' delves into the production of methane on Mars. This hypothesis compares Mars with South Africa, and draws the conclusion that the radiolysis of martian ice and water while reacting with carbon dioxide can produce enough methane to account for recently observed concentrations. Methane is important because it is hard to explain. It has a short half-life and must be replenished frequently. As recently as 2005 the public line from NASA/JPL was that the methane could be produced by volcanism. Mars' dormant Olympus Mons is the largest volcano in the solar system but auspiciously quiet. A recent study from NOAA throws into question the whole idea stating, 'If Mauna Loa is a valid terrestrial analog, our findings suggest that volcanic activity is not a significant source of methane to the Martian atmosphere.'"

6 of 95 comments (clear)

  1. Methane's short half life is a good thing.. by 3.5+stripes · · Score: 4, Funny

    as anyone with 3 male roommates can testify to.

    --


    He tried to kill me with a forklift!
  2. Good science by Da3vid · · Score: 4, Insightful

    "'If Mauna Loa is a valid terrestrial analog, our findings suggest that volcanic activity is not a significant source of methane to the Martian atmosphere.'"

    Man, I wish more of our scientific quotes sounded like this one. It lays it out straight and simple. Here is our source of info: analogy with Mauna Loa. Here is our assumption: we can project info from it onto Olympus Mons. Here is our conclusion: there is something else other than volcanic activity producing methane on Mars. I like how all that info was neatly packaged into a simple sentence. I also like how he admits the assumption... if. The thing that comes to mind are all the dinosaur shows explaining their day to day lives, zodiac signs and favorite take-out places.

  3. Re:This is interesting... by Eunuchswear · · Score: 4, Informative
    Ok,

    1. just turning C02 + H2O + energy -> CH4 + ...
      would be seriously dumb as CH4 is a much more potent greenhouse gas than C02, and stockpiling it would harder than just stockpiling the CO2 in the first place.
    2. and turning C02 + H20 + energy -> CH4 then burning the CH4 to get C02 + energy is just a nice way of wasting energy.
    3. You're not talking about a power source, just an expensive and dangerous power transmission medium.
    4. And finaly, what on earth do you mean by fragile biological processes? Artificial processes are way more fragile than biological ones.
    --
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  4. Re:Radioactive? by radtea · · Score: 4, Insightful

    The term can be applied to anything which decays with time, though radioactive decay would probably give the most attractive decay curve.

    You get the same curve from anything that has a probability of decay that is independent of time.

    If the probability of decay, destruction or loss for an individual atom is L per unit time, then for N atoms the rate of change of N is:

    dN/dt = -L*N

    and integrating gives N = No*exp(-L*t) where No is the number of atoms at some arbitrary t=0.

    So for any situation where you have a constant decay probability you will get the same curve. For methane in the Martian atmosphere the rate of decay is pretty much constant due to solar ultra-violet radiation breaking up the molecules. Therefore, if there were no source the amount of methane in the atmosphere would drop exponentially.

    --
    Blasphemy is a human right. Blasphemophobia kills.
  5. Re:No life? by Rei · · Score: 4, Informative

    No, it's not likely. Everything that we've come to learn about Martian regolith is that it's highly oxidative -- peroxides, superoxides, etc. Then factor in the problems we've known for a long time -- radiation, temperatures, lack of liquids, etc.

    If there's any life there, it must be extremely different from life on Earth to be able to withstand the oxidative environment. On Earth, Martian regolith would be a disinfectant.

    Besides, volcanism and this new theory aren't the only viable ones for methane production. Serpentization of olivine will do the trick as well. That is to say, if anywhere on the planet there is subsurface water saturated with CO2 in ever-common olivine-rich rock, it will produce methane.

    --
    Pinkypants -- my favorite!
  6. Re:No life? by SirBruce · · Score: 4, Informative

    Ahhh, the old "highly oxidative" argument.

    In truth, there has never been a test on a Martian lander designed to either confirm or identify the nature of this hypothetical strong oxidant. While there are theories that suggest that UV light should create such oxidants, the presence of a higly oxidant Martian surface has never been confirmed by experiment. Rather, it has been invoked as an EXPLANATION why certain other results, such a the Viking LRE, must be faulty.

    To date, no subsequent Mars probe has produced data that points to a strong global surface oxidation beyond the usual culprits of H20 and CO2 (which account for the rust).

    Bruce