It could be that the only way to prevent this is not to colonize Mars or not yet anyway. If so we could explore it from orbit instead using telepresence - or from Earth using autonomous rovers or a mixture of the two..
There are some scientists who think we could possibly colonize Mars without contaminating it, today. These scientists think that the surface of Mars may be so hostile to life that life can only exist underground. If that was true we could colonize the surface and yet still hopefully preserve life underground untouched, especially if it is deep underground (not so easy to see how we could avoid contaminating life that is just a couple of centimeters below the surface).
There are many suggestions nowadays of possible habitats on the surface of Mars. Those would all need to be ruled out.
Including
So the scientists who think Mars surface may still be inhospitable - well there is increasing evidence that there is liquid water on Mars. Recent study suggests that Curiosity may even have indirectly detected water at night just a short way below the surface: On Mars, Liquid Water Appears at Night, Study Suggests
But it may be just too cold or salty for life. In that particular example, that's the consensus so far, that the water they detected indirectly is thought to be too cold for life.
This liquid water is hard to impossible to detect from orbit because the amount of water involved is tiny and in most cases just below the surface of the soil or ice. And any life there equally would be sparse and probably impossible to spot from orbit. And very hard to tell if it is habitable from orbit.
So the only answer is to examine these habitats close up, probably. Surely using robotic explorers I think myself.
Anyway - so it would depend on what that turns up. If the surface is as hostile as the Moon, with maybe some water but in conditions where it is too salty or cold for any possibility of life, that might change things.
But if it is, say, as habitable as Antarctica, with some habitats where life can survive just on the edge - well I can't see how humans can avoid contaminating Mars if they land there, with life that could reproduce and once that starts, what with the global dust storms - how can you ever stop it?
And - you couldn't establish this with just one or two preliminary experiments - only after we have studied Mars reasonably thoroughly, all of the many possible habitats there.
After all we take great care not to contaminate subsurface lakes in Antarctica with Earth life and they are just millions of years of separation from the surface. So surely we should be even more careful for Mars, where there may be life that has last common origin tens of millions, or hundreds of millions, or billions of years ago, or not related to Earth life at all.
What we discover could revolutionize biology. It might be
So - I think we need to take care with Mars, just as we do with Antarctica subglacial lakes, and more so.
This is generally agreed, I don't think anyone wants to contaminate Mars with Earth life in the scientific community. But some think that the surface of Mars may be so hostile to Earth life that at some point we will be able to send humans there and explore it in a limited way without contaminating it. I just feel that it is vital that if we do that, we first evaluate really carefully to make sure that is indeed the case, as if we contaminate it with life by mistake, we can never undo that. Because there have been many times that scientists got things wrong, e.g. said flat out that life can't live in certain places, and then later on life is found in those places. In case of Mars we have quite a few scientists who have said they think that life is possible on the Mars surface so certainly don't have a consensus that it is impossible but rather a variety of views on the matter.
As for myself, I hope that Mars is habitable on the surface. Not because I have anything against colonization of Mars. If only we were like plants, grew from seeds that could be sterilized so that there is no risk of contaminating Mars, just send explorers who have been thoroughly sterilized of all microbial life. But humans would die if we attempted to do that.
If Mars is habitable, and especially if it is inhabited by non Earth based life on the surface - that would be such an amazing discovery. Is it not worth it, to discover somethign so wonderful, even if it means not colonizing Mars?
There are plenty of other lifeless places in the solar system, with the ingredients of life such as ice, organics etc (many asteroids, even Deimos moon of Mars probably) - and poles of the Moon, and we can make Stanford torus habitats eventually. We don't need Mars for humanity. And as for exploration - I think a human outpost on Deimos, say, exploring Mars by telepresence would be just as exciting and more so. Or exploring via our rovers, that involves everyone, in a way that maybe having a few astronauts in a distant part of the solar system doesn't so much, after the initial excitement.
There are some scientists who think we could possibly colonize Mars without contaminating it, today. These scientists think that the surface of Mars may be so hostile to life that life can only exist underground. If that was true we could colonize the surface and yet still hopefully preserve life underground untouched, especially if it is deep underground (not so easy to see how we could avoid contaminating life that is just a couple of centimeters below the surface).
There are many suggestions nowadays of possible habitats on the surface of Mars. Those would all need to be ruled out.
Including
- Life that just uses the night time humidity. Some lichens, cyanobacteria and black yeasts have been grown in Mars simulation chambers in conditions similar to those that you get in cracks in rocks on Mars somewhat shielded from UV light, and are able to metabolize and photosynthesize using just the night time humidity.
- Warm seasonal flows - these features on Mars form only when the temperatures go above 0C and are not correlated with winds or dust storms, instead they extend gradually during the spring and summer and fade away in winter. The leading hypothesis for these is that in some way they are associated with water, perhaps salty brines that flow just below the surface
- After observation of droplets on legs of the Phoenix lander, then scientists have tried to reproduce them in Mars simulation chambers. Last year Nilton Renno succeeded in producing them rapidly, within minutes, on ice / salts interfaces and he thinks that droplets of water may be widespread over Mars especially in the upper lattitudes.
- Several other possibilities, e.g. the "flow like features" close to the poles seem to be probably caused by water through the solid state greenhouse effect (a process that happens on the Earth and causes a liquid water layer about half a meter below deeply frozen blue ice in Antarctica).
So the scientists who think Mars surface may still be inhospitable - well there is increasing evidence that there is liquid water on Mars. Recent study suggests that Curiosity may even have indirectly detected water at night just a short way below the surface: On Mars, Liquid Water Appears at Night, Study Suggests
But it may be just too cold or salty for life. In that particular example, that's the consensus so far, that the water they detected indirectly is thought to be too cold for life.
This liquid water is hard to impossible to detect from orbit because the amount of water involved is tiny and in most cases just below the surface of the soil or ice. And any life there equally would be sparse and probably impossible to spot from orbit. And very hard to tell if it is habitable from orbit.
So the only answer is to examine these habitats close up, probably. Surely using robotic explorers I think myself.
Anyway - so it would depend on what that turns up. If the surface is as hostile as the Moon, with maybe some water but in conditions where it is too salty or cold for any possibility of life, that might change things.
But if it is, say, as habitable as Antarctica, with some habitats where life can survive just on the edge - well I can't see how humans can avoid contaminating Mars if they land there, with life that could reproduce and once that starts, what with the global dust storms - how can you ever stop it?
And - you couldn't establish this with just one or two preliminary experiments - only after we have studied Mars reasonably thoroughly, all of the many possible habitats there.
After all we take great care not to contaminate subsurface lakes in Antarctica with Earth life and they are just millions of years of separation from the surface. So surely we should be even more careful for Mars, where there may be life that has last common origin tens of millions, or hundreds of millions, or billions of years ago, or not related to Earth life at all.
What we discover could revolutionize biology. It might be
- Early life that hasn't evolved as much as Earth life - not got all the machinery of the modern cell
- Proto life - not quite life but complex organics and maybe cell like structures
- Life that has evolved in a different direction from Earth life maybe not based on DNA at all
- It could be lifeless. That also would be very interesting, if habitable and lifeless - what happens to a planet with no life on it. That could lead to new understanding of the role of life in our own ecosystem and how much is due to life, and how much due to chemistry and geology
So - I think we need to take care with Mars, just as we do with Antarctica subglacial lakes, and more so.
This is generally agreed, I don't think anyone wants to contaminate Mars with Earth life in the scientific community. But some think that the surface of Mars may be so hostile to Earth life that at some point we will be able to send humans there and explore it in a limited way without contaminating it. I just feel that it is vital that if we do that, we first evaluate really carefully to make sure that is indeed the case, as if we contaminate it with life by mistake, we can never undo that. Because there have been many times that scientists got things wrong, e.g. said flat out that life can't live in certain places, and then later on life is found in those places. In case of Mars we have quite a few scientists who have said they think that life is possible on the Mars surface so certainly don't have a consensus that it is impossible but rather a variety of views on the matter.
As for myself, I hope that Mars is habitable on the surface. Not because I have anything against colonization of Mars. If only we were like plants, grew from seeds that could be sterilized so that there is no risk of contaminating Mars, just send explorers who have been thoroughly sterilized of all microbial life. But humans would die if we attempted to do that.
If Mars is habitable, and especially if it is inhabited by non Earth based life on the surface - that would be such an amazing discovery. Is it not worth it, to discover somethign so wonderful, even if it means not colonizing Mars?
There are plenty of other lifeless places in the solar system, with the ingredients of life such as ice, organics etc (many asteroids, even Deimos moon of Mars probably) - and poles of the Moon, and we can make Stanford torus habitats eventually. We don't need Mars for humanity. And as for exploration - I think a human outpost on Deimos, say, exploring Mars by telepresence would be just as exciting and more so. Or exploring via our rovers, that involves everyone, in a way that maybe having a few astronauts in a distant part of the solar system doesn't so much, after the initial excitement.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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