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Transferal of life

  1. Aug 30, 2012 #1
    Signs point to life on Mars, billions of years ago, even before Earth..
    Is it possible that Asteroid impacts, launched rocks to Earth from Mars, and the bacteria in these rocks evolved on Earth? If so how likely is this scenario?
     
  2. jcsd
  3. Aug 30, 2012 #2
    IF evidence of life is
    found on Mars, and IF it shares similar bio-chemical properties, then the odds will be higher than what we can estimate today. For now, your idea falls in the realm of theoretically possible, and nothing more. Life could form anywhere and be blasted in to space by asteroid impacts. But until we see evidence for this, how can anyone say how likely it is?
     
  4. Aug 30, 2012 #3
    Well take into consideration, it is our closest neighbor.. There was a period of heavy bombardment. And the fact is, it would be impossible for the Earth not to contain thousands of LBS of Mars rocks.. And since Mars did have water, and if it had DNA based bacteria. It was transferred to Earth, because Mars would of had life before Earth did. And if we ever find DNA based life on Mars in a rock etc.. That would mean we are Martians..
     
  5. Aug 30, 2012 #4

    Chronos

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    Why would you think martian life predated life on earth?
     
  6. Aug 30, 2012 #5

    Ryan_m_b

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    What makes you think abiogenesis on Mars was more likely to happen than on Earth? This question is entirely unanswerable at the moment. Firstly because we don't yet have a comprehensive theory of abiogenesis and secondly because our knowledge of martian history is so incomplete.
     
  7. Aug 30, 2012 #6
    Martian predators running wild :rofl:
     
  8. Aug 30, 2012 #7

    HallsofIvy

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    No, it isn't. Not counting the moon, Venus is our closest neighbor. Venus is about half as far from the earth as Mars.

    How does that follow?

     
  9. Aug 30, 2012 #8
    I have heard people refer to Mars in this way before. I think he meant "closest" as in most similar, and not physical distance. I also think people need to write more clearly to prevent misunderstanding! :-)
     
  10. Aug 30, 2012 #9

    Ryan_m_b

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    Is it though? I don't know the answer to that I'm genuinely curious.
     
  11. Aug 30, 2012 #10
    I don't know either. I was explaining a common alternative meaning of that phase in popular culture.

    Of the two neighbours, Mars and Venus, Mars would be my first bet for human habitation and for what we might recognise today as life. I will have to research if Venus today is similar to the climate of primordial Earth. In terms of colonisation, I don't know if I prefer Mars or the moon, but I will take either over Venus. Mars is further than Luna but water means greater potential for self-sufficiency.
     
  12. Aug 30, 2012 #11

    mfb

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    In our solar system, probably, if mars really had an atmosphere and liquid water over significant timescales and if venus was not completely different before. Mercury is too close to the sun, all other planets are gas giants (and too far away from sun, so the moons do not help) and all minor planets are too small or way too far away from sun.
    In other planetary systems, there are planets more similar to earth than mars ;).
     
  13. Aug 30, 2012 #12
    There are actually small creatures called "Tardigrades" that are able to survive for extended periods of time in space, and some scientists think that this may be how life got on earth. There is a word for this theory, but I can't remember it...
     
  14. Aug 30, 2012 #13

    Ryan_m_b

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    I think you hit the nail on the head with popular culture. I'm always sceptical when people trump the colonise Mars idea. With a bit more water at the poles and a wisp of an atmosphere the Moon would be just as habitable. Bear in mind the Martian atmosphere is a small fraction of the pressure of Earth's and Mars has no biosphere at all for us to survive in. In fact we still don't have any real evidence to suggest how healthy land animals are if they are conceived, born and raised in low gravity let alone how well ecosystems would work.

    The whole habitability comparison seems to be like arguing whether it is more survivable to be shot in the face at point blank or blown up with a MOAB six feet away.
    Panspermia.
     
  15. Aug 30, 2012 #14
    Both Mars and Moon would need domes to live in.

    I believe the argument for Mars was:

    2H2O (drink) → 2H2 (fuel) + O2 (breathe)
     
  16. Aug 30, 2012 #15

    Ryan_m_b

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    Agreed, domes and closed ecosystems. Plus a large society to fill a specialised labour pool and a wealth of industries to support them...
    Pretty weak argument IMO.
     
  17. Aug 30, 2012 #16

    mfb

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    You do not have to produce this from water, and you need the oxygen to burn hydrogen anyway. Both O2 + C <-> CO2 (food/breathing) and 2H2O <-> 2H2 + 22 (as energy storage) can be used as closed cycles.
     
  18. Aug 30, 2012 #17
    I'm not keen on either Mars or moon. Priority 1 has to be large asteroids approaching Earth.
     
  19. Aug 31, 2012 #18
    Couple questions..

    Is it true there are dried up river, deltas etc.. on Mars?

    Therefor there must of been water, IF there were single celled organisms that sprouted to life during this time, it is a FACT that they would be transferred to Earth during the Heavy Bombardment. Correct?

    This could very well be how life started off, since a lot of people think life came from amino acids from asteroids in the first place...

    Mars life (if true) would pre date Earth life, because around the time of the rivers on Mars, Earth was still in a cooling phase after the Mars size rock hit Earth, causing the Moon..
     
  20. Aug 31, 2012 #19

    Ryan_m_b

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    There are outflow channels on Mars but I'm not sure if it's definitive if they are caused by water.
    No. Just because there is water doesn't mean life arose. Even if life was there it's not a certainty it would be jettisoned off in a meteor. Even if it was jettisoned off there's no certaintly it would survive. And even if all that were true there's no certaintly that particular meteor would hit Earth.
    Who? The Miller-Urey revealed long ago that amino acids could have arisen on a primordial Earth.
    What sources do you have to support this?
     
  21. Aug 31, 2012 #20
    It appears "Mars == Nearest Neigbour" is no longer the domain of popular science. Look at the caption for the diagram at http://cars9.uchicago.edu/gsecars/LVP/publication/News/X-rays%20reveal%20secrets%20of%20Mars%27%20core.htm [Broken]

    I said in another thread that I am not surprised science journalists can't get it right when the source is ambiguous.
     
    Last edited by a moderator: May 6, 2017
  22. Aug 31, 2012 #21
    Well i more than likely it would be water..

    If these single cell organisms can survive all the ice ages, extreme heat and the meteor impacts that hit Earth, why wouldn't life be able to survive deep inside the cracks of the asteroid going through space?


    You must not be too familiar with the early life of our solar system.. Before there were the 8 planets, there were quite more planets. Over time they all collided making the planets with stable orbits we have today.

    Is the has the Moon been orbiting Earth ever since the Earth formed 4.5 billion years ago?
     
  23. Aug 31, 2012 #22

    Ryan_m_b

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    The time to accept that it is is when the burden of proof has been met, not before.
    Species survive because they were able to avoid these things you speak of. A single celled organism that would be utterly denatured at 50-100C would not survive a meteor impact. That's not to say it wouldn't be impossible for an extremophile to be ejected from some adjacent land but it is by no means a certainty.
    I'm familiar with this, what is your point? How does this relate to me asking you for sources to back up your claim that Mars would have evolved life before Earth? Given that the event that caused the Martian global dichotomy is dated at around 4gya it seems unlikely.
    No but that is irrelevant to everything that I have said.
     
  24. Aug 31, 2012 #23
    So the point about the Moon I was making was as following; Earth never had life before the Moon. Therefor life would not spring into existence on Earth until.. 500 million years after the Moon was formed. Now Mars didn't go through this phase, therefor their life would have a head start on Earths life.

    And sure life could very easily survive an asteroid impact, after all the dinosaurs did. They died off due to lack of sunlight etc. So why couldn't basic germs deep inside the rocks that have escaped the gravity of Mars survive? The rocks that were projectiles were not magma or melted rock, they were still solid, therefor life could very easily survived through the vacuum of space and the trip to Earth.

    Lets say during heavy bombardment, this scenario happened, life was than brought to Earth from Mars rock and sprouted life on Earth.. If scientists find cells in Mars rocks that are the same as here on Earth, is this enough proof to say that life came from Mars?
     
  25. Aug 31, 2012 #24

    Ryan_m_b

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    Three things:
    1 - What about the formation of the Martian Global Dichotomy that happened at a similar time as the Moon's formation?
    2 - Where does this half a billion year figure come from? Citation please or admit that you made it up or the thread will be locked.
    3 - Life is not a teleological process. It's a drunkards walk through a fitness landscape determined by environmental conditions acting on random mutations. Taking one population and splitting it into multiple identical, separated samples will result in wildly different results after time.
    If you realise how silly this statement is why say it?
    I didn't say they couldn't I said it wasn't a guarantee that it would happen.
    No, if we found cells on Mars that matched Earth as it is now it would be an indicator that they got there very recently.

    The type of life that existed 3.5-4 billion years ago was so utterly different to anything we have now that I doubt there would be any way to conclusively say it was related to terrestrial life (ignoring the fact that life that ancient is not well preserved enough for that kind of study). Relating to what I said before if life had been evolving on Mars for hundreds of millions or billions of years after it spread to Earth it would be so different from us that it is highly unlikely there would be any similarity beyond the basic biochemicals used. And without a theory of abiogenesis and an understanding of primordial Mars we couldn't say if it was more likely if they transferred or both favoured the evolution of that kind of life.
     
  26. Aug 31, 2012 #25
    I did not say it has been evolving on Mars after it spread to Earth, I said it was evolving than asteroid impact causes some life to come to Mars, and all life is wiped out on Mars during this event... This is very plausible, I didn't make up figures, this is a rough estimate according to the heavy bombardment phase and http://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System
     
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