Originally Answered: Why is it important that we colonize Mars?
When that happens, Mars might briefly become the most habitable planet in the solar system, before it, too, gets too hot as the sun gets even hotter - eventually the most habitable region of the solar system for humans may extend to Jupiter's orbit.
Meanwhile it's potential is as a place to explore, rather than colonize, fascinating place. See my Ten Reasons NOT To Live On Mars - Great Place To Explore
Right now, Earth is by far the most habitable planet in the solar system, and there is no way that we can make Mars as habitable as Earth - certainly not in less than a few thousand years, with present day technology - and quite probably never.
And it's not a place to survive extinction events - the best place to survive anything like that is on the Earth.
First, such events are very rare. Chance of one as big as 1-10 kms across hitting us by 2100 is something like 0.0001% or less, a lot less than many would guess, I think. And also - though that seems pretty huge - it is tiny compared with the sort of asteroid you'd need to cause extinction of humans on Earth. Not had anything that big since the first few hundred million years of the solar system - aren't any craters anything like big enough in the geological record.
For the 10 km ones, the dinosaurs didn't have our technology and we'd have plenty of warning for something as big as that - at least enough to spend some months building shelters, if we can't actually deflect it. And some would survive anyway - in submarines if nothing else (tsunami are a surface phenomenon - a submarine in the sea unless right next to the impact wouldn't notice it). But surely would be many survivors - and after any of these disasters - then Earth is the best place to rebuild civilization in the inner solar system. So you want your survivors here, not on Mars where they are six months travel from where they will want to be to rebuild civilization.
And - current ideas for making Mars habitable are short term anyway on the geological timescale because it can't retain a thick atmosphere long term, and has no continental drift to return CO2 to the atmosphere when it turns into rock.
By the time any creature still on Earth really needs Mars a half billion years from now, any present day terraforming attempt would have long since lost all its volatiles and would be in a worse state than if we never did anything with it.
What's more we don't know if humans can withstand the low gravity, it's got no protection from cosmic radiation, or solar flares, it's got half the sunlight of Earth - and worst of all of course - very dry - and no atmosphere to speak of.
Nobody would want to live in a place like that if it was on Earth. Even have to make all your own oxygen. And can't go out of doors without spacesuits. If you trip and fall and tear your spacesuit, or damage its faceplate etc, you don't just get a bad scratch or a bruise, you die. Damage your spacesuit and you can't go out at all until it is mended.
And houses built with a layer of some meters of regolith covering them to protect from radiation - and built like tanks to withstand 10 tonnes per square meter outwards pressure, no windows or tiny windows probably.
Greenhouses really hard to make - a "garden shed" type greenhouse or a standard "polytunnel" useless would just blow apart under the pressure - probably have to be spherical or hemispherical and made of some thick clear plastic again able to withstand several tons per square meter of pressure outwards.
It would obviously be a major struggle just to survive at all and you'd be totally dependent on high technology.
Sort of like living permanently in a submarine, closest equivalent we have on Earth.
And what it is valuable as, is a planet that was almost identical to Earth in the early solar system, complete with oceans, thick atmosphere etc. And somehow lost nearly all its water.
So - either it has life -and that life might be different from Earth life - or it doesn't have life - and if so - what happens to a planet like Earth but without life on it? Would have had organics, we know that much because comets and meteorites deliver plenty of organics to Mars every year. Did it develop complex chemistry? Something that is almost like life, but not quite? Or did it actually get as far as life, independent origin? Or did it share life with Earth via meteorites?
The last thing we want to do while trying to answer all those questions is to go to Mars and find life - but the life we find is life we brought there ourselves.
So - we should only send humans there if totally sure that they will not bring life to the planet themselves in a way that would confuse our experiments and studies.
A few years ago many scientists thought that was possible. But - I think would be hard to establish this now. Because there are many proposals now for potential habitats on the surface of Mars where liquid water may be possible. Some with quite good evidence. Until those have been examined in situ on the ground, it's not going to be possible to rule them out - and I think myself is a good chance that we will find at least micro-habitats - a few mms thick layers of salty brine - even in one of the suggested habitats - melt water below a layer of clear ice - at around zero degrees centigrade (rather warm for Mars).
And - if that is what happens - well we should welcome it and be excited at the prospect of finding - maybe ETs - microbial ETs okay or lichens or similar perhaps - but still - could be life with a completely different basis from Earth life if we are lucky.
And - a human ship incoming to Mars - well apart from anything else, it could crash with a hard landing. After that - any measurements that detected life on Mars would surely be rather dubious as probably just detecting life brought there on the crashed human spaceship.
So - I vote against sending humans to colonize Mars at this stage!
But they may be very useful in orbit around Mars, controlling rovers on the surface via telepresence. And that would be an exciting way to explore Mars that would engage everyone, with live streaming 3D immersive surroundings from the Mars surface.
Or we might not need to send them to Mars if we can manage controlling our spacecraft from Earth via simulated real time as used in computer games, as is one possibility for Mars for the future.
Anyway we will see how it pans out. I think myself that NASA by putting so much focus on colonization of Mars as its end goal is missing out on the more exciting things it could do such as build missions that have as their end goal finding out about Mars and whether it has life or not. For some time the search for life on Mars seems to have taken rather a back seat to colonization - e.g. successor to Curiosity - with its caching - it is caching samples even though the exobiologists advise that this is not the best way to search for life on Mars - and has this oxygen generation experiment that seems to be mainly targetted towards idea of sending humans there - and for a long time exobiologists have tried to get NASA to send their experiments to Mars with no success.
It also pulled out of the partnership with the ESA over the interesting ExoMars project, it was going to contribute a whole suite of instruments which it developed, the UREY suite, some time back - but pulled out ofr budgetary reasons, leaving the ESA to go it alone in partnership with Russia for the launcher.
So - partly because colonization - I can't see that it achieves anything. Partly because of issues with search for life on Mars or study of what pristine Mars is like - and then partly also - because it distracts attention and takes resources away from missions that would be of much more value.
I'm fine with trying out ideas for colonizing Mars on Earth - who knows - may be useful some day for something. Maybe even that once we find out more about Mars - that there does turn out to be value in colonizing it after all - and that it doesn't interfere with science studies etc.
But right now - no, and shouldn't do space policy based on the idea that colonizing Mars is inevitable.
Any more than - e.g. exploring Antarctica on the basis that it is inevitable that we will colonize Antarctica so research stations and expeditions there should devote much of their energy to trying to find out ways to grow crops in Antarctica etc.
To me this idea that space policy for Mars should be based around eventual colonization is pretty much exactly like the idea that Antarctic research should be based around eventual colonization of Antarctica.
Or indeed that missions to the sea bed should be based around eventual colonization of the sea bed, or missions to explore deserts, say to the Atacama desert - should be based around colonizing them, etc etc.
But to go there to explore - that's a very different story. Then you'd take care not to contaminate it as that's the very reason you go there, because you are interested in the place itself, in its own right, and want to find out about it.
Anyway as it is, I don't think they are going to be able to prove that their surface missions to Mars will satisfy the requirements of Planetary protection. They are optimistic that they will but haven't given any explanation of how they will achieve this, and I think when they get to the details they will find it is far harder than they thought. And it would have to be passed internationally, in consultation with many expert exobiologists etc.
How is that going to be possible, given these many potential habitats on the surface of Mars, and the possibility of a hard landing of a human occupied ship?
See also
Robert Walker's answer to Has NASA purposefully sent any life forms to other planets?
Robert Walker's answer to What are some major ethical issues that are essential yet not actively discussed about with regards to sending astronauts on space exploration flights?
And other answers here
And on Science20
- Trouble With Terraforming Mars
- Why Mars is NOT a Great Place to Live - Amazing to Explore From Orbit - with RC Rovers, and Nature Inspired Avatars
- How Valuable is Pristine Mars for Humanity - Opinion Piece?
- Would Microbes From This Astronaut Make It Impossible For Anyone To Terraform Mars - Ever?
- Imagined Colours Of Future Mars - What Happens If We Treat A Planet As A Giant Petri Dish?
- Why We Can't "Backup Earth" On Mars, The Moon, Or Anywhere Else In Our Solar System - Opinion Piece
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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