First, there may very well be life on Mars at present. It had an ocean in the early solar system, most agree now, for a few hundred million years. And conditions now though very hostile may be survivable by some Earth organisms in favoured places. We just don't know yet. The possibility of habitable conditions on Mars can't yet be ruled out, so our spacecraft have to be carefully sterilized to make sure they don't introduce Earth life to Mars. Especially so if they go to the "special regions" in the higher latitudes, and the "warm seasonal flows", they will need to be sterilized to a high level - one of the main reasons we send spacecraft to the equatorial regions which don't require such high levels of sterilization with the current guidelines.
That doesn't mean there is life there now. But the possibility of life is high enough that all the scientists involve agree that we have to keep taking precautions and indeed recently the chance has increased through various new discoveries suggesting at least a slender possibility of habitable conditions there - and some would say that it is even likely that there are habitats there of some sort. By habitats, we mean habitats for microbes, perhaps lichens as the most complex, and likely to be a harder place for them to live even than the dry valleys in Antarctica but possibly still just about survivable.
As for lakes, from time to time a meteorite or comet will hit the poles of Mars and the heat would create a subsurface lake that would remain liquid for of order of a thousand years or more. If there is Mars life then it might well seed these lakes. They can also form as a result of volcanic activity.
For more on this, Will We Meet ET Microbes On Mars? Why We Should Care Deeply About Them - Like Tigers
Are There Habitats For Life On Mars? - Salty Seeps, Clear Ice Greenhouses, Ice Fumaroles, Dune Bioreactors,...
That doesn't mean there is life there now. But the possibility of life is high enough that all the scientists involve agree that we have to keep taking precautions and indeed recently the chance has increased through various new discoveries suggesting at least a slender possibility of habitable conditions there - and some would say that it is even likely that there are habitats there of some sort. By habitats, we mean habitats for microbes, perhaps lichens as the most complex, and likely to be a harder place for them to live even than the dry valleys in Antarctica but possibly still just about survivable.
As for lakes, from time to time a meteorite or comet will hit the poles of Mars and the heat would create a subsurface lake that would remain liquid for of order of a thousand years or more. If there is Mars life then it might well seed these lakes. They can also form as a result of volcanic activity.
For more on this, Will We Meet ET Microbes On Mars? Why We Should Care Deeply About Them - Like Tigers
Are There Habitats For Life On Mars? - Salty Seeps, Clear Ice Greenhouses, Ice Fumaroles, Dune Bioreactors,...
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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