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I If there is life on Mars should people stay home?

  1. Oct 4, 2015 #1


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    Is it really possible to send people to Mars and not risk microbial contamination of any life there ? If the recent discovery of liquid water raises the possibility of life, should any human missions be delayed until this is understood better? ISTM if there are any living Microorganisms on the planet, their ecosystem must be fragile and who knows if a few of our E. coli would wipe them out
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  3. Oct 4, 2015 #2


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    Such missions are going to be "self-delaying" for a loonnngggg time.
    "Fragile?" In a surface environment favorable to formation of perchlorates? Kinda doubt it.
  4. Oct 5, 2015 #3
    My guess is we'll do what we always do. Sample it. Catalogue it. Then trample all over it.
  5. Oct 5, 2015 #4
    Earth life would have a hard time getting started on Mars, it's fine tuned for living here. Mars is a significantly different ecosystem: the water's toxic, the air in almost non-existent, radiation is way more intense. It may survive for a few days, but earth life requires a lot of energy to work and I just don't think Mars has enough of it.

    That said, humans do live in a cloud of our own microorganisms, we will exhale billions of times more microbiology during our stay there than could ever cast away on a probe, so the danger levels are significantly higher.
  6. Nov 29, 2016 #5
    The problem is getting some serious study. (probably a good idea considering the unknowns involved)
  7. Dec 2, 2016 #6
    We would need to know what life is on Mars before we could determine if our microbes could contaminate it.

    This at least, is unlikely. If there are any microorganisms living on Mars, they are very much suited to their environment. Any organisms we introduce will most likely not be suited to that environment. The healthiest e.coli specimen you can find will Boil, Freeze, Suffocate, Starve and Roast... all basically simultaneously, on the surface of Mars.

    If it is any consolation, the beefiest Martian microorganisms would be appallingly ill adapted for life in a habitat for humans on Mars.
  8. Dec 2, 2016 #7


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    There is another thing in our 'favour' here. The situation on Mars has been stable for a long long time (I think we can say that) and that could mean that evolutionary forces on any existing life would not favour rapid changes. The Earth's organisms have been changing (and needed to change) at a very high rate, recently. I would suggest that it would be much more likely for the Earth's life forms to do ok in a strange place than would the Martian forms (if they actually exist).
    For billions millions of years, the Earth lifeforms were prokaryotic (Bacteria etc) it is only quite recently that life on Earth developed into eukaryotic ( all the rest of us), which means we would probably be in competition with some very slowly adapting life forms. The Earth is full of Introduced Species so why would we expect Space to be any different - It's what we DO.
  9. Dec 2, 2016 #8
    As long as money can be made from it somehow you can guarantee people wont leave it alone
  10. Dec 13, 2016 #9
    It's more important to ensure that any microbes from Mars never make it back to Earth. The advantage of Mars One is that no one will be returning to Earth.
  11. Dec 13, 2016 #10
    On that subject.
    The revised schedule, which shifts the first launch of robotic missions until the early 2020s and the first human mission until the early 2030s, comes as Mars One becomes a publicly-traded company on the Frankfurt Stock Exchange in Germany and seeks to raise funding.
  12. Dec 13, 2016 #11
    Oh well, if it's all about return on an investment, it's a good idea to present the investors with plans that are at least vaguely credible.
  13. Dec 13, 2016 #12


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    Not really convinced that's true.

    As others have mentioned, it is extremely unlikely that Marian microbes would be able in infect Earth life. And that's really the only danger of Martian microbes arriving here.

    OTOH, Earth microbes can contaminate Martian materials, confounding our study of possible Martian life.
  14. Dec 14, 2016 #13
    I guess it's ultimately a matter of opinion. I would advocate for the colonization of outer space even if this comes at the expense of preserving or studying endemic life forms.
  15. Dec 14, 2016 #14
    It's practically a given that econazi (the extremist wing of environmentalists) will be all over it and screaming their heads off "LEAVE MARS ALONE YOU DIRTY HUMANS!!!"

    I already have seen one person on nasaspaceflight.com forum seriously advocating a total ban on manned Mars landings on the grounds that (wait for it) even if there is no currently life there, it might arise there sometime in the next few billions of years.
  16. Dec 14, 2016 #15
    Just out of interest, when we send out unmanned crafts, do bacteria from earth travel with them and enter mars's orbit? Maybe this sounds a little silly but obviously some bacteria can survive the harshest of conditions
  17. Dec 14, 2016 #16
    The assembly and launch teams do try very hard to make space probes completely sterile using UV and other methods,
    however 100% sterilization cannot be guaranteed.
    This applies also to deep space missions like those investigating Jupiter and Saturn environment.
    These are deliberately crashed into the giant planet's atmosphere at the end of the mission, to avoid possibly contaminating one if it's moons.
    (The giant planet itself has atmosphere so thick that the probe is bound to be incinerated (and crushed).
  18. Dec 15, 2016 #17
    Here is a NASA piece on PP. :smile:
  19. Dec 15, 2016 #18


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    Another disadvantage of life on Mars: The harsh conditions could mean it is much slower in its evolution. Advantageous things that took billions of years to develop on Earth could be missing for life on Mars. In the same way current life on Earth can easily out-compete every newly forming proto-life here, life from Earth might be much more efficient with all the metabolism steps and so on.
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