Mars for exploration, not colonization, at least not yet - we could mess it up badly

[robertinventor]

In last night's Star Gazing Live they talked a bit about Mars, and as usual, as a place that we might colonize eventually. It comes up many times on Sky at Night and on Star Gazing Live and every time the idea is that Mars is a place that humans might live eventually, as the main interest in the planet.

But there are lots of things wrong with this idea. I know that NASA have it as their objective for Mars eventually - but that is lead by politics and by Mars Society such as Robert Zubrin.

Just to say who I am for context, I'm a mathematician been interested in space exploration since a child in the 1970s, am an armchair astronomer rather than an observer, in the Isle of Mull in Scotland, and recently wrote a number of articles on this topic  for science20 which have received a fair  bit of attention recently, including guest appearance on Dr Livingston's space show (Seattle radio program) in the US.

Mars is far from ideal for colonization. It is worse than the harshest deserts on Earth. Really to my mind it makes no sense at all to colonize it. We should colonize the deserts here or the sea beds, if the aim is to find somewhere to live.

There are ideas to terraform Mars, yes - but those are sketchy and the most optimistic of them make it a 900 year process. Most think it would take millennia, one estimate by Chris McKay for the time needed to get to an oxygen atmosphere on Mars like Earth is 100,000 years. On the Earth it took millions of years to get to an oxygen rich atmosphere so even that is a massive speed up.

We have no experience of terraforming anything, and can't even create a small closed habitat in space yet.

And there are so many things that can go wrong.

Mars is further from the sun (half the light for photosynthesis), third of the gravity of Earth (we don't even know if humans can live long term in 1/3 g yet), that also means it needs three times as much atmosphere for the same pressure on the surface, it has no magnetic field (which prevents Earth's atmosphere getting stripped by the cosmic wind and flares), it's axial tilt varies because it has no Moon, so much that sometimes it has equatorial ice belts.

Its orbit is far more elliptical leading to a different climate in the two hemispheres and major storms sometimes global every two years - those are no hazard at present because the atmosphere is a near vacuum - but think what they would be like on a terraformed Mars with full Earth pressure - it is also closer to the asteroid belt with 5 times the meteorite influx of Earth - in early stages of terraforming then the atmosphere would be no protection and that means a 1 megaton impact every three years somewhere on the surface of Mars.

It is lacking in nitrogen - particularly not enough for a buffer gas in the atmosphere - and has no continental drift - this is what returns CO2 to our atmosphere on Earth long term and is the main thing that gets Earth out of its snowball phase - a real hazard for Mars with its further distance from the sun - it just goes on and on. Yes it does have a near 24 hour day but that is about the only close resemblance to Earth.

And the bottom line is, that we have absolutely no experience of terraforming. Is no good reason to suppose that it would work, we might be lucky on Earth. Maybe most exoplanets similar to Earth fall into different end conditions. The Gaia hypothesis is about cycles that help to maintain Earth - but - even if you agree to the weak hypothesis - still it also depends on continental drift and the magnetic field as well - and doesn't tell you that planets will automatically form a Gaia - or that the Gaia if it does form will be an Earth like one. Mars could form cycles that lead to some very different end phase e..g an atmosphere poisonous to humans (maybe rich in methane), or most likely just revert back to a snowball phase. Mars is so cold you would call it a snowball planet  except that it is also so dry that there isn't enough surface ice to cover the entire planet. If it had enough then even the equator would be white.

See my science20.com article: Trouble with Terraforming Mars.

So Mars is not a place to colonize in my view in the near future. And even for centuries into the future, if we did find a way to colonize it - it would still be far worse than Earth would be even immediately after a giant asteroid impact. So is no second home for Mars, the idea that it is, when you look at the facts, borders on the absurd in my view.

You could  build self contained habs on Mars indeed, paraterraforming as they call it, covering it with greenhouses. But you can do that in space too - and without the extreme cold of Mars (shielded from the sun all night and only full sunlight at midday for a surface hab) - and without the dust storms - and really the atmosphere - extracting CO2 from a near vacuum - is hardly much of an advantage for Mars over space. 

And - the total area of Mars is same as land area of Earth. Total area you could construct as space habs, with enough cosmic radiation shielding to be as safe from cosmic radiation as the Earth - is a thousand times the land area of the  Earth  - and that's just using material from the asteroid belt. 

We have a planet bound perspective, naturally, but if you do the calculations, then free space habs seem a much better bet long term if you are really keen on space colonization. Then for the near future the poles of the Moon seem an enticing target, especially the peaks of eternal light at the poles, year round solar energy no nights, and close by water deposits. And without the huge supply issues for Mars - can only get there every two years might be a wait of two years to e.g. get a replacement part if your heating or air supply machinery fails, new spacesuit, or whatever it is you need.

There is a lot of good new science to be done on the Moon, and plenty to discover. Including the fascinating possibility of meteorites from Early Earth from the late heavy bombardment, with organics preserved from that time with no later contamination from Earth. One scientist jokingly suggested we might also eventually  find ammonites on the Moon - is not as silly as it might sound - the larger impacts on Earth send some of the material into space only lightly shocked. Most interesting of all, if there is any evidence of the really early stages on Earth - when there would be most debris sent towards the Moon - and also - have almost no evidence left on Earth - just a few zircons embedded in later rocks.

Then the next step after that might be a space colony close to Earth, or at least making frequent flybys of Earth. Some NEOs are a few hundred meters across and for instance Nereus has enough material in it to create cosmic radiation shielding for an entire Stanford Torus.

See my Asteroid Resources Could Create Space Habs For Trillions; Land Area Of A Thousand Earths 

But Mars is absolutely fascinating for biology. It had global oceans in the early solar system and may even have seeded Earth with life. And the amazing thing about Mars is that most of it has been in a deep freeze for billions of years. Ideal conditions to preserver the organics in pristine conditions.

I know we haven't found life there yet - but we have hardly looked. Only Viking has looked for life explicitly.

Mars is fascinating for biology - but also - it is likely to be a long and quite difficult search. 

That's because, any organics on the surface get thoroughly damaged by cosmic radiation over millions of years, and if from ancient Mars have been there billions of years. Also there seems to be some process, probably chemical, that removes organics from the surface because we should see some organics there deposited by meteorites - and don't find the expected levels.

So any organics on the surface or near the surface from ancient Mars are probably long gone. There may be present day life on Mars - but it is likely to be perhaps a cm or so below the surface. The most likely places include the warm seasonal flows - evidence of water flowing, every year - the newest ones were even in equatorial regions - just enough to dampen the soil - but that would be enough for life.  Rare - just a few streaks here and there over the surface of Mars. Never sent any rover anywhere near them and of course can't spot subsurface microbes from orbit. Populations would also be too small to make any significant difference to the Mars atmosphere.

Also deliquescing salts - this is a habitat that may be suitable for life over much of the higher lattitudes. Also solid state greenhouse effect below the ice sheets. Many ideas here been put forward by biologists for close to surface habitats (may also be regions of liquid water kilometers below the surface of Mars where temperatures and pressures are just right for subsurface life - and also - possibility of geothermal heating and trapped layers of water closer to the surface).

For ancient Mars, it could fill in a truly enormous missing gap in our understanding of the evolution of life.  About half of the evolution of complexity of life happened before the earliest things we have record of (as measured using non redundant nucleotide complexity which evolves at a steady rate on a log plot). Also the smallest things we recognize as living cells are 200 nm across (0.2 microns). The earliest cells were probably more like 40 nm across. No way a modern cell could arise by chance in one go - and the earliest cells were probably themselves preceded by less complex precursors and protobionts.

There are many theories of abiogenesis - see the wikipedia article - but they are theories with no evidence available to chose between them.

Also most interesting case, Mars could have XNA based life - life that doesn't use DNA as Earth life does.

See my How Valuable is Pristine Mars for Humanity - Opinion Piece?

So not just looking for ancient life on Mars but also, stages before life. This evidence is probably there, even if it didn't evolve to life. There must be good evidence there of what happens to a sea rich in organics left for a few hundred million years - and if it didn't evolve life - still that also is a good ground truth for expolanets and understanding of evolution. It must have formed cell like structures and protobionts as those form readily even in small laboratory experiments. 

So there is good evidence there, almost certainly, very good bet that there is. But it is a few meters below the surface and you also need to know where to look. So don't expect to find it on your first few missions to Mars unless amazingly lucky.

And sample return is of no use here, from the surface highly unlikely to tell us anything about biology - at least - no more than we already know from the Maritan meteorites we already have. Unless present day life on Mars exists and is abundant enough to find easily (seems unlikely) - in that case then a sample return is a hazard for Earth and needs extreme caution.

Even if you dig ten meters down and retrieve a sample - how do you know it is of biological interest? Chances are it is not. You need to send biological instruments to Mars. That is the conclusion of a group of exobiologists who have studied the issue. And we have instruments we could send too, 

There are miniaturized DNA sequencers (BIOG), highly sensitive biosignature detectors (one will be sent on ExoMars hopefully in 2018 - first explicitly biology targetted experiment to Mars since Viking), there is the updated labelled release testing for chirality - there is a miniaturized scanning electron microscope in development - and of course optical microsocopes, haven't yet sent anything to Mars with the resolution to spot individual cells unless they are really huge. 

I think humans do have a major role to play in this - for exploring Mars.

But not from the surface. Humans on the surface would be clumsy - in pressurized spacesuits - but worse than that - they would contaminate the planet. For sure with dead DNA - and the ultra scientific experiments devised by the biologists can detect a single DNA molecule or a single amino acid in a sample

Also a much higher risk of contaminating Mars than for robots. With the warm seasonal flows, and deliquescing salts in high lattitudes, are almost certainly habitats that could be contaminated - and even if they don't land near them - with the global dust storms to send materials imbedded in  a dust grain throughout Mars - also iron oxides so shield from UV - and some microbes are now known to be UV resistant withstand hours and even days of Mars surface simulated sunlight - and some lichens that can even grow and metabolize with apparently no ill effects using just the night time humidity on Mars and partially shaded sunlight locaton on the rocks in a simulated environment.

And if you get a hard landing on Mars which breaches the human habitat, or if humans die on Mars, then that is an immediate huge contamination of Mars with Earth microbes, over a hundred trillion microbes on and in a human - in over 10,000 species most not well studied.

So surely humans on the surface have a greatly increased risk of contaminating parts of the planet with dead life and quite possibly entire planet with living organisms too and would be clumsy also. Are not needed for mining as is sometimes said, best method is probably an automated mole in case of Mars - is different from Earth, and in their clumsy spacesuits they would have difficulty mining even a few meters.

But where they would be great is in orbit. With the complex terrain on Mars and the amount of decision making needed, then we could really do with humans "on the spot". This was worked out in a NASA mission idea a few years back called 

[robertinventor]

Sorry don't know what I did, posted it mid edit, maybe pressed some key combination that was a shortcut to post it??

Can't seem to edit it. But anyway is clear enough so far but broke off before an important bit.

What I wanted to add is that there was a mission plan called HERRO looked into ideas for telerobotic exploration of Mars from Orbit. It uses a slowly precessing near sun synchronous Molniya orbit - a bit like the ones the Russians used for communication over polar regions - but this is equatorial and comes close to Mars twice a day over the sunlit side of Mars so you get to do telerobotic exploration of the entire surface of Mars in sunlit conditions from close up with hardly any delay. Is also an easy orbit to get into, is close to a Mars capture orbit, delta v to get to it would be about the same as the delta v to land on the Moon.

Anyway they worked out it would cost far less than a surface mssion - and what's more - also get much more science done - because no need to put on spacesuits, in shirt sleeves environment do the exploring right away - and you can control several rovers at once and jump about from one to another at will (e.g. leave one doing an analysis while you go over to the other to drive it or to gather samples or drill or whatever).

All in all, though they didn't do detailed costs and it is from a few years back, but a mission like this, you are talking about, I would imagine, an order of magnitude lower cost than a surface mission. I think both would cost far more than the optimistic estimates - because we have no experience yet of sending humans away from Earth and the ISS is very dependent on its proximity to Earth for servicing and supply. .But - I think with a big budget it would be feasible to mount a telerobotic expedition to Mars orbit. 

Nowadays - you'd do it surely with lots of miniature avatars on the surface not the big rovers suggested for HERRO, or not just those. Would have some big ones also, some successor to curiosity equipped for telerobotic work - but able to move far faster. You could use Robert Zubrin's ideas for creating fuel from hydrogen seed stock on Mars - and then have rovers that can be driven at high speed over the surface of Mars, even tens of miles an hour if safe. You could drive all the way from Curiosity landing site to Mount Sharp - with human drivers operating from orbit - within a single day. With miniature rovers could explore - is an old plan to send miniature gliders to fly up and down the Valles Marineres - well update that and have humans in orbit flying them. Tiny avatars to go into caves, lots of ideas.

I think this is a far more interesting and imaginative future than an attempt at a colonization which would surely fail and also contaminate the planet. No way we are ready for a centuries and millennia long attempt at terraforming Mars even if it is possible - and we should do nothing that could change the planet irreversibly while we know so little about it.

But responsible exploration - this we can do  and would be an exciting thing to do as well and inspiring.

For the telerobotic exploration see my Telerobotic Avatars On Mars With Super-Powers ("Teleporting" from orbit) - Search For Life - And Long Term Exploitation 

[ronin]

But Mars is absolutely fascinating for biology. It had global oceans in the early solar system and may even have seeded Earth with life. And the amazing thing about Mars is that most of it has been in a deep freeze for billions of years. Ideal conditions to preserver the organics in pristine conditions.

In the early life of the solar system Mars would have been frozen, with or without water, those marks show the presence of a liquid, which does not mean water. The sun was cooler then so Mars was outside the habitable zone = no liquid water, by our definition, it is now only just creeping into the habitable zone. So the idea of global oceans is more then a little doubtful, as to seeding Earth with life there is I would say no real chance.

When people talk of Mars they forget that the conditions in the early stages of this solar system are not as they are now.

Mars will have been a deep freeze in the early stages of it's life (first 3 billion years) and still is, give it about another billion years and it will be warmer owing to the increased output of the sun. Just now it is not and in the early stage of the solar system it certainly was not. Mars has not it would seem got colder, it is getting warmer. Check the sun's output over time.

As for fascinating for biology, not one sign of biology has been found, no sign of organics either, so far absolutely none has been identified. At this stage that equals fascinating for nothing. Stop reading the science fiction, Heinlin's books on Mars are not fact. Try stellar evolution to get an idea of what will have occurred on Mars as that is where Martian climate and conditions are defined. Just the same as ours have been and will be.

It also takes energy (heat) for life to get going, so as it has been in a deep freeze for billions of years by your own words when did life get going and evolve. A deep freeze will prevent life developing and evolving so there would be nothing to preserve. Which so far matches all the evidence, nothing there.

We cannot migrate to Mars, there is nothing there and that includes an atmosphere (slightly useful to air breathing mammals), bit cold as well, -55C being the most common value. And in the coming millions of years the atmosphere will get less even if the temperature rises slightly. Do you see a bustling civilisation on Antartica ? That is warmer and has an atmosphere.

One big mistake that seems to be coming to light is people apply an earth like situation to other planets and places, which have generally been shown to be completely wrong. So far I cannot think of one scenario where applying this earth like criteria has been right.

[robertinventor]

In the early life of the solar system Mars would have been frozen, with or without water, those marks show the presence of a liquid, which does not mean water. The sun was cooler then so Mars was outside the habitable zone = no liquid water, by our definition, it is now only just creeping into the habitable zone. So the idea of global oceans is more then a little doubtful, as to seeding Earth with life there is I would say no real chance.

When people talk of Mars they forget that the conditions in the early stages of this solar system are not as they are now.

Mars will have been a deep freeze in the early stages of it's life (first 3 billion years) and still is, give it about another billion years and it will be warmer owing to the increased output of the sun. Just now it is not and in the early stage of the solar system it certainly was not. Mars has not it would seem got colder, it is getting warmer. Check the sun's output over time.

As for fascinating for biology, not one sign of biology has been found, no sign of organics either, so far absolutely none has been identified. At this stage that equals fascinating for nothing. Stop reading the science fiction, Heinlin's books on Mars are not fact. Try stellar evolution to get an idea of what will have occurred on Mars as that is where Martian climate and conditions are defined. Just the same as ours have been and will be.

It also takes energy (heat) for life to get going, so as it has been in a deep freeze for billions of years by your own words when did life get going and evolve. A deep freeze will prevent life developing and evolving so there would be nothing to preserve. Which so far matches all the evidence, nothing there.

We cannot migrate to Mars, there is nothing there and that includes an atmosphere (slightly useful to air breathing mammals), bit cold as well, -55C being the most common value. And in the coming millions of years the atmosphere will get less even if the temperature rises slightly. Do you see a bustling civilisation on Antartica ? That is warmer and has an atmosphere.

One big mistake that seems to be coming to light is people apply an earth like situation to other planets and places, which have generally been shown to be completely wrong. So far I cannot think of one scenario where applying this earth like criteria has been right.

Oh I think you are about 2 or 3 years out of date there. That's what they used to think.

But now, there is really strong evidence of an early ocean on Mars that must have lasted for a few hundred million years. There is also evidence for a second ocean about a billion years later which was short lived. 

The most convincing evidence is in the form of the shore lines which have been traced all the way around the Northern hemisphere low areas. To start with the evidence wasn't too convincing because it didn't seem to be level. But then after they took account of the way the shape of Mars altered - and back tracked - then it turned out that the shorelines were level after all.

Then just last year there was really strong evidence. Study of features that resemble deltas feeding into the old oceans. The delta was flowing the right way - which they could tell by the 3D images from the ESA orbiter which give depth information - and had features similar to those of Earth deltas as they flow into oceans.

It is hard to understand theoretically how this happened - and is one of the things the Maven mission hopes to answer is how Mars lost its early thick atmosphere and deep oceans - but the evidence that it did happen is pretty much incontrovertible now.

For organics - I'm basing this on science not science fiction. The meteorites and comets would have delivered abundant organics to Mars. Present day Mars also - should be enough to be equivalent to the amount of organics you have in a typical Earth desert, just from meteorite impacts on Mars. For some reason this is not found which means there is some process on Mars which is actively destroying these organics. It would also destroy any remains of organics from billions of years ago.

So for the scientists studying this, it is not at all surprising that we have found no organics on Mars yet. It is disappointing. but not surprising.

[robertinventor]

Agree that Mars is getting more habitable as time gets on - in a billion or two years time it might well be more habitable than Earth - as our seas boil dry, and Mars begins to warm up. 

Depends how much water there is on Mars and if there is enough CO2 for an atmosphere and for human habitation (or rather whatever our descendants are a billion years from now)  might need a buffer gas - but who knows what the intelligent life will be like by then. 

Later on as the sun gets hotter, then Jupiter's moons become habitable also. Mars would be in the habitable zone for a short time but maybe for long enough to be a useful stepping stone to Jupiter for some forms of life in natural course of events.

Eventually when it becomes a white dwarf, would need to migrate back again close to the sun. I think though - that there may well be space colonies by then and those would cope with it more easily - just shade the sun if it is too hot, add more mirrors to reflect more sun into the habitat if too cold - or move further out or closer to the sun - and probably have fusion power for the sunlight anyway pretty soon like within a few decades.

I think we simply can't tell what Mars would or would not be useful for in the future, and that may become clearer as we learn more about it as we explore it. Chris McKay thinks that one possibility is that we might want to - what I call his idea - "Mars Form" Mars - make it a better place for whatever life is there already if there is life there now. Another idea is that if there is no life there or even if there is but primitive e.g. those tiny 40 nm early life type cells - then it could be amazing to turn the clock back and try to restore the global oceans to Mars and the thicker atmosphere - not for humans - but rather keep Earth life well away if we can - so you can actually study the ancient Mars pretty much like going back in time, to see how such an ocean works, one that's only had organics and beginnings of evolution for a few hundred million years.

And if Mars has XNA, different from Earth DNA again would be fascinating to make it a place where the XNA can flourish and see what happens to it on a planetary scale. Maybe have our own exoplanet in same solar system but different forms of life on it.

Once you acknowledge that Mars does not have to be ear-marked for colonization and in fact is not really that good for colonization, many other possibilities open up for you. And the preliminary exploration from orbit costs much less and I think once properly explained would fascinate the public more than a short lived space race to try to be first to land colonists on Mars. And also be of long term interest too as the scientists and the others using the robotic avatars on the surface explore Mars in real time.

Look at how much interest there is in robotic missions to Mars already. Now imagine that e.g. the whole of Curiosity's expedition to date happens within the first few hours of the humans arrival at Mars - with more capable instruments also - and that you have several of those going on at once + also flying and miniaturized avatars. I think would be pretty fascinating - and all as live feeds from Mars (once we crack the transmission of HD video from Mars to Earth probably using laser technology) - so you can watch it all from EArth in light speed delayed live feed if you want to.

[robertinventor]

Just to add - this is not at all a criticism of StarGazing Live or Sky at Night. It's a great show, really enjoy them both. Was Patrick Moore was probably one of the main reasons I got so keen on astronomy back in the late 60s. And this idea that Mars is a place to go to, in order to colonize, as our main objective is what everyone says in all the news stories on the subject and is the US political point of view on the subject.

But - when you look at it closely then it really doesn't seem to make any sense. And I've talked about this widely, discussed it with scientists of various disciplines, engineers, exobiologists, astronomers - and none of them have come up with any sound reasoning that makes sense of the idea to colonize Mars surface instead of exploring it from orbit - most haven't thought about it at all and just accept that it is the objective.

But when you put forward the reasoning here - and get a discussion going - often it takes some time for them to think it through and reflect on it - but eventually just about everyone agrees on this - that if you are looking for a place to live then Mars is not an ideal place to colonize at all for at least a few centuries even if terraforming did work - and that it is best explored from orbit rather than on the surface.

The ones who think we should still go there are people who just say - but wouldn't it be so tantalizing to orbit Mars never able to go there in person - or - that we just must stand on the surface, to explore the orbit is not the same at all. Like they want to go to the surface and even when there is no scientific or practical reason still want to do it even if it contaminates Mars.

You can't argue with people who say that - it is a point of view and if you value humans landing on the surface of Mars as highly as that over all the other benefits then you will still want to do it no matter what. But the thing is you aren't doing that just for yourself. By irreversibly contaminating Mars you would spoil it also for the whole of humanity - and legally - all the signatories of the Outer Space treaty - all the countries in the world almost - with a few exceptions such as N. Korea..

I don't think it is right for anyone to make a unilateral decision of that sort - not even a US president if he were to decide that was the US main objective and not a private Netherlands company - and I think anyway - that they would find the legal obstacles to it insurmountable as the time came when they had to prove to COSPAR that they have adequate provisions in place to land on the surface of Mars without contaminating it.

I think they often think that they would do it once the exploration phase is over, imagining that in a decade or so we would know enough about Mars - but the exploration phase has barely started for biology and will surely last at least several decades and probably much longer given the complex terrain and geological history and huge area same as Earth surface - and may well lead to discoveries that make us decide we want to keep Mars pristine or postpone any terraforming or even start to think about Mars forming etc.