Yes we might be able to send life to Mars that can reproduce there. If your aim was just to introduce Earth life to Mars you could introduce the cyanobacteria tested by DLR in Germany which is able to survive in just the Martian atmosphere without water, some lichens also. It's only been tested in Mars simulation chambers for a month or so, but the researchers think there is a chance they could survive on Mars, maybe even in the equatorial regions.
You could also send haloarchaea which might be able to survive in some of the briny liquid flows there. Also some black fungi that might be able to survive there in some habitats if they exist.
There are many lifeforms we could send if our aim was to get Earth life growing on Mars. And it would be comparatively easy to do, probably. If that was the aim, we could have done it maybe even right back in the 1970s, perhaps send an RTG to the polar regions to keep the ice melted, and add green algae, and you'd have a little pool of algae that would probably survive there very nicely indeed, and might then spread out over Mars.
The solar storms and cosmic radiation are not a problem for microbes - some can survive and live just fine even in the intense radiation of reactor cooling ponds. UV & Cosmic Radiation On Mars - Why They Aren't Lethal For The "Swimming Pools For Bacteria"
But our aim is the exact opposite of that at present. We want to find out if there is life on Mars already, and what it is. The last thing we would want to find there is life that we brought there ourselves. So - all the space faring nations except Syria, even North Korea, have ratified the Outer Space Treaty - which amongst other things commits us to protect Mars and other places in space from "harmful contamination" and we do our best to sterilize our spacecraft following recommendations developed in a committees of international scientists at COSPAR.
If in the future we were to decide we don't need to protect Mars any more in this way - well introducing Earth life is an irreversible step and lots to go wrong. So I think even then we probably wouldn't rush into it, but would think carefully about what we want to do and when. I hope so anyway!
What we can do though is to test introducing life to space habitats, for instance on the Moon - there is no risk of contaminating the Moon with Earth life. And Mars is far more inhospitable than you might think from the photos and the movies. If you ask which Mars is most like - Earth - or the Moon - I think in many ways it is most like the Moon, with a near vacuum, the cold and so on. It does have a day length similar to Earth and a very thin atmosphere but it is so thin it is nearly a vacuum. And it is red instead of gray. With lots of dust in its atmosphere. And it was habitable in the past but lost most of its water and atmosphere since then. It is only barely habitable now. Indeed there is hardly any place on Earth as uninhabitable as Mars. The cold dry heart of the Atacama desert, and the dry McMurdo valleys in Antarctica - where there is no ice because it is kept so dry by high winds - they are the closest analogues we have to Mars. But are thought to be more habitable than Mars.
And introducing life to Mars won't magically make it habitable. That's a bit like going to Antarctica and hoping to make it habitable by dropping some microbes on the continent.
Mars may well have life already. We don't know yet. Hard to find, low numbers, rare, maybe also only in some places and not in others.
It might well have had lots of life in the distant past. But it lost its atmosphere, and ocean, and - if it still has life it is in small populations surely at least on the surface. We can't expect to change that by adding life from Earth. It would need to involve mega-engineering of some form - large mirrors, greenhouse gas factories or whatever - but even then - would it work? And would it not be better to use all that effort to help Earth instead?
And - terraforming is a project that would take millennia, maybe even millions of years, and may go wrong easily. So no hurry to start. We don't know what our descendants a thousand years from now will want. And our descendants even a century from now might have much better ways to do things, and the thing is whatever clumsy attempts we do now could push Mars into some state that is hard to recover from, e.g. if we introduce a problematical microbe to the planet either by accident or through ignorance.
See also Trouble With Terraforming Mars
Imagined Colours Of Future Mars - What Happens If We Treat A Planet As A Giant Petri Dish?
You could also send haloarchaea which might be able to survive in some of the briny liquid flows there. Also some black fungi that might be able to survive there in some habitats if they exist.
There are many lifeforms we could send if our aim was to get Earth life growing on Mars. And it would be comparatively easy to do, probably. If that was the aim, we could have done it maybe even right back in the 1970s, perhaps send an RTG to the polar regions to keep the ice melted, and add green algae, and you'd have a little pool of algae that would probably survive there very nicely indeed, and might then spread out over Mars.
The solar storms and cosmic radiation are not a problem for microbes - some can survive and live just fine even in the intense radiation of reactor cooling ponds. UV & Cosmic Radiation On Mars - Why They Aren't Lethal For The "Swimming Pools For Bacteria"
But our aim is the exact opposite of that at present. We want to find out if there is life on Mars already, and what it is. The last thing we would want to find there is life that we brought there ourselves. So - all the space faring nations except Syria, even North Korea, have ratified the Outer Space Treaty - which amongst other things commits us to protect Mars and other places in space from "harmful contamination" and we do our best to sterilize our spacecraft following recommendations developed in a committees of international scientists at COSPAR.
If in the future we were to decide we don't need to protect Mars any more in this way - well introducing Earth life is an irreversible step and lots to go wrong. So I think even then we probably wouldn't rush into it, but would think carefully about what we want to do and when. I hope so anyway!
What we can do though is to test introducing life to space habitats, for instance on the Moon - there is no risk of contaminating the Moon with Earth life. And Mars is far more inhospitable than you might think from the photos and the movies. If you ask which Mars is most like - Earth - or the Moon - I think in many ways it is most like the Moon, with a near vacuum, the cold and so on. It does have a day length similar to Earth and a very thin atmosphere but it is so thin it is nearly a vacuum. And it is red instead of gray. With lots of dust in its atmosphere. And it was habitable in the past but lost most of its water and atmosphere since then. It is only barely habitable now. Indeed there is hardly any place on Earth as uninhabitable as Mars. The cold dry heart of the Atacama desert, and the dry McMurdo valleys in Antarctica - where there is no ice because it is kept so dry by high winds - they are the closest analogues we have to Mars. But are thought to be more habitable than Mars.
And introducing life to Mars won't magically make it habitable. That's a bit like going to Antarctica and hoping to make it habitable by dropping some microbes on the continent.
Mars may well have life already. We don't know yet. Hard to find, low numbers, rare, maybe also only in some places and not in others.
It might well have had lots of life in the distant past. But it lost its atmosphere, and ocean, and - if it still has life it is in small populations surely at least on the surface. We can't expect to change that by adding life from Earth. It would need to involve mega-engineering of some form - large mirrors, greenhouse gas factories or whatever - but even then - would it work? And would it not be better to use all that effort to help Earth instead?
And - terraforming is a project that would take millennia, maybe even millions of years, and may go wrong easily. So no hurry to start. We don't know what our descendants a thousand years from now will want. And our descendants even a century from now might have much better ways to do things, and the thing is whatever clumsy attempts we do now could push Mars into some state that is hard to recover from, e.g. if we introduce a problematical microbe to the planet either by accident or through ignorance.
See also Trouble With Terraforming Mars
Imagined Colours Of Future Mars - What Happens If We Treat A Planet As A Giant Petri Dish?
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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