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Homework Help: Lifetime of CO2 in Mars atmosphere

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  1. Mar 7, 2012 #1
    1. The problem statement, all variables and given/known data
    Estimate the lifetime of CO2 in the atmosphere of Mars.


    2. Relevant equations



    3. The attempt at a solution
    What is he asking? How long has the CO2 been in the atmosphere? It just seems rather vague.
     
  2. jcsd
  3. Mar 7, 2012 #2

    gneill

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    Staff: Mentor

    Mars is losing its atmosphere. Heavier molecules last longer than lighter ones. Think about temperatures, kinetic energy distributions, escape speeds,...
     
  4. Mar 7, 2012 #3
    So is he asking to estimate how long until there is about 0% CO2 in the atmosphere? Or an average time before a molecule escapes?
     
  5. Mar 7, 2012 #4

    gneill

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    Staff: Mentor

    At a guess I'd say estimate a time constant for the decay (##~e^{-t/\tau}~##) and call ##\approx 5\tau## the lifetime.
     
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