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Just for Fun, Terraforming!

  1. Apr 22, 2012 #1
    could it be possible to use sf6 (sulfur hexafluoride) + photosynthetic bactera + hydrogen to transform mars's atmosphere into a breathable atmosphere that is also warm enough for survival? If somone could produce ozone efficiently, would it be possible to create some kind of radiation shield on mars?

    Don't give me hate, I just wanted to spark the idea, though i'd love suggestions to improve it... and if its not possible (even if one has unlimited resources) then come up with your own ideas!
     
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  3. Apr 22, 2012 #2

    tiny-tim

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  4. Apr 22, 2012 #3
    good question, haha, maybe we're going to need to bring in hydrogen from jupiter or something to beef up the atmosphere (probably very expensive)
     
  5. Apr 23, 2012 #4
    As Mars warms up its regolith will desorb extra carbon dioxide. Depending on extra sources of dry ice around the poles, then the super-greenhouse gases should warm things up enough for a Mount Everest level of surface pressure, at least in a big depression like Hellas. Might be enough to begin propagating bioengineered plant life.
     
  6. Apr 23, 2012 #5
    Mars lacks a unified magnetosphere. Whatever atmosphere is produced would be blown into space by the solar wind.
     
  7. Apr 23, 2012 #6
    Just like on Venus?
     
  8. Apr 23, 2012 #7
    http://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core

    "The weak magnetosphere around Venus means that the solar wind is interacting directly with the outer atmosphere of the planet. Here, ions of hydrogen and oxygen are being created by the dissociation of neutral molecules from ultraviolet radiation. The solar wind then supplies energy that gives some of these ions sufficient velocity to escape the planet's gravity field. This erosion process results in a steady loss of low mass hydrogen, helium, and oxygen ions, while higher mass molecules such as carbon dioxide are more likely to be retained. Atmospheric erosion by the solar wind most probably led to the loss of most of the planet's water during the first billion years after it formed. The erosion has increased the ratio of higher mass deuterium to lower mass hydrogen in the upper atmosphere by a multiple of 150 times the ratio in the lower atmosphere.[62]"
     
  9. May 4, 2012 #8
    During Venus's first billion years, the Sun's solar wind was much greater. The present day erosion rate is minor by comparison. A few kilograms of atoms per second will mean the atmospheres last billions of years. Hardly an impediment to human settlement or establishment of a moderately long-lived biosphere. Our own, left to natural processes, will coming to a crashing end in 0.5 billion years when the CO2 runs out. Maybe.
     
  10. May 4, 2012 #9

    Ryan_m_b

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    A huge problem for any terraforming proposal is the ecology. You can't just dump life on a planet and expect it to work. You also can't just introduce organism by organism and expect that to work well. We'll need a far greater understanding of ecological webs before we can start isolating which ones are necessary/desirable and what support they need in the form of other organisms (who in turn need other organisms who in turn...).

    Of course all of that is compounded by the problems of whether or not you can get the right soil, right sunlight, right length of sunlight, right pressure, right temperature and right gravity. Whilst there have been some experiments on development under micro gravity there's a significant gap in our knowledge regarding long term species survival under different gravity (and then we get the knock on effects in the ecosystem if that particular environmental trait leads to selective advantage to some organisms and disadvantage to others).
     
  11. May 4, 2012 #10

    phyzguy

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    Another huge problem for terraforming is the length of time required. As I understand it, it took over a billion years to generate the oxygen atmosphere on Earth. When plants started producing oxygen, all of the initial oxygen got used up oxidizing minerals in the sea and on land. This process has to go mostly to completion before oxygen begins to accumulate in the atmosphere. All of this takes a very long time by human standards. To live off the Earth, I think we will either need to (1) build space habitats, (2) find a planet that is already suitable, or (3) use genetic engineering to adapt to existing planets.
     
  12. May 4, 2012 #11

    Ryan_m_b

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    The problem with option 2 is that even if we suggest that future astronomy locates a habitat and characterises it as having water, the right atmosphere etc to get there we are going to need to live in a stable environment for a very long time (unless we propose some sort of high-relativistic transport). But a bigger problem is that of potentially lethal allergic reactions from superantigens, possible parasite/infections (this one is very unlikely though), inability to digest native organisms and existing ecosystems out competing our own.

    Three is itself very speculative so we don't need to go there.

    The first example remains the only viable one. Of course it doesn't necessarily have to be a habitat in space, it could also be a ground settlement. However we do run into the question of why we would bother but that's a far bigger and incredibly ideological discussion.
     
  13. May 4, 2012 #12

    phyzguy

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    I agree that space habitats are the only viable aletrnative - at least in the near term. As to why, the best response is to quote Robert Heinlein, "The Earth is just too small and fragile a basket for the human race to keep all its eggs in. " If we don't get off it, we are clearly doomed to extinction.
     
  14. May 4, 2012 #13

    Ryan_m_b

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    This is where I should "gotcha!" :tongue2: the eggs-in-one basket argument rests on the premise that there are potential threats to life on Earth for which the only solution is to leave. However the technologies we would need to leave often remove the potential threat in the first place.

    Just one example: to live cut off from Earth we'll need the ability to build and maintain stable ecosystems. If we can do that then we also have the technology to maintain and even reboot Earth's biosphere if it fails. Therefore any argument on the basis of ecological collapse disappears.

    If proponents of space colonisation were pimarily concerned with survival or resources they would focus on the various better solutions to those threats rather than space, yet they do so. Hence I go back to my previous conclusion; arguments for space are ideological justified.
     
  15. May 4, 2012 #14

    phyzguy

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    We should do both - improve the sustainability of life on Earth and begin to move off it. We know of things in the far future, such as the increase in luminosity of the sun, that will make the Earth uninhabitable despite any conceivable effort. Remember that the sun's 'fuel tank' currently reads just under a half full. We also know that the Earth has been subjected to repeated extinction events that we do not fully understand. The 'Great Dying' at the end of the Permian era 250 million years ago wiped out most life on Earth. What if whatever caused it happens again? If another 'dinosaur killer' asteroid like the one that caused the Chicxulub crater came along, it would probably be beyond our capability to move unless we start building a space-based civilization. I don't say we need to do this tomorrow, but we need to start moving in this direction.
     
  16. May 4, 2012 #15

    Ryan_m_b

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    Don't get me wrong, I like the ideology of living in space and elsewhere. To respond to specific points:

    1) Regardless of what happens humans will not be around for millions of years, let alone billions. Simple evolution will take care of that.

    2) The End-Permian mass extinction was big but it is only one of six mass extinctions, one of which is potentially occuring now. Mass extinctions happen over such a long time period that dealing with them isn't too much of an issue beyond dealing with small scale ecological change/collapse. Which if we wish to live off of Earth we will have to understand to an extent where monitoring, predicting and manipulating for sustainability is a must.

    3) A meteorite impact would be bad but we could funnel our hypothetical space colonisation plan funds into better meteorite protection and harm reduction technologies. I.e. divert as many asteroids as we can, for those we can't simply modify our cities to weather the storm and then use our ecological know-how to fix the damage to the biosphere after.

    In summary I don't think we need to move to space at all. All the technologies we would require would have better and cheaper uses on Earth. For that reason I rarely support arguments for space technologies on the basis of "the spin offs could help on Earth" which to me is backwards; it should be funding Earth based technologies on the basis that "the spin offs could help space". To finish how I started though: I do have an affinity to the ideology behind moving from Earth.
     
  17. May 5, 2012 #16
    Terraforming of Mars would have to be done only after it is adeqately explored. This will reduce the possibility that our tampering with the Martian environment might result in extinction of Martian indiginous life. That could take a very long time since it would involve both surface and subsurface exploration.
     
    Last edited: May 6, 2012
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