We don't know what is on Mars. Chris McKay has suggested that until we know this, we need to explore Mars in a reversible way. If we find life on Mars that's independently evolved, not related to Earth life, for instance, then there could be a strong case for reversing the effects of our exploration to date - removing all materials from Mars that could be contaminated with Earth life. We don't have the technology to do that yet but in the future we may be able to do that.
Whatever we do - I think this is a decision that would need to be made on basis of knowledge and understanding, not on hopes or fears and guesses.
So far we have not yet sent any missions to Mars to look for life since Viking. some think that the Viking labelled release may have detected life. If so then there may be life almost anywhere on Mars. Curiosity certainly can't rule that out, because it is not equipped with instruments able to detect it. Curiosity couldn't detect life if you placed it, for instance, at the heart of the Atacama desert and asked it to look for life.
Suppose some ET, not knowing about Earth, sent a rover to land on a random spot on Earth and it chose the hyper arid core of the Atacama desert and sent Curiosity there - it would report back that there is no life on Earth.
Now - the hyper arid core of the Atacama desert, one of the least habitable places on Earth, is probably more habitable than the most habitable place on Mars. And it does have life, but life that is extremely hard to detect. ExoMars will have instruments that could detect life there, but Curiosity doesn't.
So what chance that Curiosity would discover present day life on Mars?
Also there are many ideas for habitats on Mars, especially since the recent discovery by Nilton Renno of the possibility of water forming on ice / salt interfaces almost anywhere on the surface of Mars.
If those habitats are uninhabited also - they are of extraordinary interest to science too. What happens to such habitats if there is no life around? Why is there no life there? What happens to the organics that continually arrive on Mars from meteorite and comet impacts, on a planet with habitats for life, but no life?
Obviously we need a baseline understanding of what Mars is like now, before we decide what to do next.
This is built into the Outer Space Treaty and also into the COSPAR guidelines for robotic spacecraft to Mars that they have to be sterilized to prevent contaminating Mars, especially if they go to regions of Mars or can impact into regions of Mars that may have present day habitats - the so called "special regions" of Mars.
So - human missions shouldn't be treated any different in my view. After all we take great care to not contaminate the lakes below the ice in Antarctica which have been cut off from the surface for at most a few millions of years- how much more important to protect Mars? It may have never had any exchange of life with Earth for all we know - or if it has - is far more isolated than these under ice lakes in Antarctica.
So in short, I can't see colonization going ahead, despite the optimistic views of many that think it will somehow be able to pass planetary protection. It's going to take decades of careful research, even with greatly improved technology and more finance than is available now, before we can begin to understand Mars well enough to begin to have an idea of the range of possibilites for what might happen - and what a human landing on the planet might potentially do to it - or a hard landing scattering debris, our food, air, and human bodies over the planet (realistically, we have to recognize this as a distinct possibility of any human mission to Mars).
It's not as if we colonize everywhere on Earth. We don't colonize the bed of the sea. We don't colonize deserts. We don't colonize mountain tops. We don't colonize the under ice lakes in Antarctica. We don't colonize the upper atmosphere where we could build floating cities such as Buckminster Fuller's "cloud nine".
All of these are far far more habitable than Mars. Would cost just a tiny fraction of the cost of a habitat on Mars to build habitats in any of these places. Not least, because we can breath the air, and we can build our habitats with ordinary building technology without the need to contain atmosphere inside the habitats with ten tons per square meter outwards pressure, and temperatures fine and water available and gravity just right for humans. Even a floating cloud city, in the Earth atmosphere, sci. fi. though it seems to us - is actually quite practical, Buckminster Fuller worked out (using his lightweight but robust constructions and floating just due to the extra heat of the air inside the city) and far less sci fi. than a Mars colony, cost far less, far easier to build etc etc.
It is just so much easier for us to build cities on the Earth's surface than floating in the sky, so the idea has never taken off, even though the technology should work fine, and sky cities are far easier to build than space colonies. So why would we want to build cities in space? Except for some other reason to go there other than colonization? In case of Mars the main other reason, only other reason I know of so far, is to go there to explore the planet with learning about the origins of life as the main objective. But if that is your reason for exploring Mars, then planetary protection should come top of your list of priorities.
Which I think myself will mean that we explore it remotely from Earth, or possibly by telepresence from Mars orbit, with humans operating telerobotic avatars on the surface, at least until we know a whole lot more about the Mars surface, and whether there is life there, or what there is, whether it has uninhabited habitats, and if so how those work, etc - than we do now. As for what we do after we truly understand how Mars works - well hopefully then our decisions can be based on understanding of conditions there, and at least some idea of the range of possible consequences of our actions - rather than on blind fears and hopes.
Whatever we do - I think this is a decision that would need to be made on basis of knowledge and understanding, not on hopes or fears and guesses.
So far we have not yet sent any missions to Mars to look for life since Viking. some think that the Viking labelled release may have detected life. If so then there may be life almost anywhere on Mars. Curiosity certainly can't rule that out, because it is not equipped with instruments able to detect it. Curiosity couldn't detect life if you placed it, for instance, at the heart of the Atacama desert and asked it to look for life.
Suppose some ET, not knowing about Earth, sent a rover to land on a random spot on Earth and it chose the hyper arid core of the Atacama desert and sent Curiosity there - it would report back that there is no life on Earth.
Now - the hyper arid core of the Atacama desert, one of the least habitable places on Earth, is probably more habitable than the most habitable place on Mars. And it does have life, but life that is extremely hard to detect. ExoMars will have instruments that could detect life there, but Curiosity doesn't.
So what chance that Curiosity would discover present day life on Mars?
Also there are many ideas for habitats on Mars, especially since the recent discovery by Nilton Renno of the possibility of water forming on ice / salt interfaces almost anywhere on the surface of Mars.
If those habitats are uninhabited also - they are of extraordinary interest to science too. What happens to such habitats if there is no life around? Why is there no life there? What happens to the organics that continually arrive on Mars from meteorite and comet impacts, on a planet with habitats for life, but no life?
Obviously we need a baseline understanding of what Mars is like now, before we decide what to do next.
This is built into the Outer Space Treaty and also into the COSPAR guidelines for robotic spacecraft to Mars that they have to be sterilized to prevent contaminating Mars, especially if they go to regions of Mars or can impact into regions of Mars that may have present day habitats - the so called "special regions" of Mars.
So - human missions shouldn't be treated any different in my view. After all we take great care to not contaminate the lakes below the ice in Antarctica which have been cut off from the surface for at most a few millions of years- how much more important to protect Mars? It may have never had any exchange of life with Earth for all we know - or if it has - is far more isolated than these under ice lakes in Antarctica.
So in short, I can't see colonization going ahead, despite the optimistic views of many that think it will somehow be able to pass planetary protection. It's going to take decades of careful research, even with greatly improved technology and more finance than is available now, before we can begin to understand Mars well enough to begin to have an idea of the range of possibilites for what might happen - and what a human landing on the planet might potentially do to it - or a hard landing scattering debris, our food, air, and human bodies over the planet (realistically, we have to recognize this as a distinct possibility of any human mission to Mars).
It's not as if we colonize everywhere on Earth. We don't colonize the bed of the sea. We don't colonize deserts. We don't colonize mountain tops. We don't colonize the under ice lakes in Antarctica. We don't colonize the upper atmosphere where we could build floating cities such as Buckminster Fuller's "cloud nine".
All of these are far far more habitable than Mars. Would cost just a tiny fraction of the cost of a habitat on Mars to build habitats in any of these places. Not least, because we can breath the air, and we can build our habitats with ordinary building technology without the need to contain atmosphere inside the habitats with ten tons per square meter outwards pressure, and temperatures fine and water available and gravity just right for humans. Even a floating cloud city, in the Earth atmosphere, sci. fi. though it seems to us - is actually quite practical, Buckminster Fuller worked out (using his lightweight but robust constructions and floating just due to the extra heat of the air inside the city) and far less sci fi. than a Mars colony, cost far less, far easier to build etc etc.
It is just so much easier for us to build cities on the Earth's surface than floating in the sky, so the idea has never taken off, even though the technology should work fine, and sky cities are far easier to build than space colonies. So why would we want to build cities in space? Except for some other reason to go there other than colonization? In case of Mars the main other reason, only other reason I know of so far, is to go there to explore the planet with learning about the origins of life as the main objective. But if that is your reason for exploring Mars, then planetary protection should come top of your list of priorities.
Which I think myself will mean that we explore it remotely from Earth, or possibly by telepresence from Mars orbit, with humans operating telerobotic avatars on the surface, at least until we know a whole lot more about the Mars surface, and whether there is life there, or what there is, whether it has uninhabited habitats, and if so how those work, etc - than we do now. As for what we do after we truly understand how Mars works - well hopefully then our decisions can be based on understanding of conditions there, and at least some idea of the range of possible consequences of our actions - rather than on blind fears and hopes.
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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