Why Elon Musk's Colony on Mars in 2020s is Unfeasible - What Could We Do - Really?
    By Robert Walker | April 21st 2014 04:46 AM | 43 comments | Print | E-mail | Track Comments
    Actually physically getting humans and their life support to Mars is likely to be feasible. But there is much more to it than that.


    First - they have to land there safely. Landing on Mars is far harder than anywhere else in the inner solar system, if you need a soft landing. 

    The problem is - that the atmosphere is so thin, it's not enough to slow you down to a soft landing even with huge parachutes. But it is still enough so that as soon as you hit the Mars atmosphere you are totally committed.

    This Hubble photograph of Mars shows the two polar caps, and clouds over the Hellas impact crater. - more Hubble photographs of Mars.
    In the case of the lunar landings, right up to the last minute, the astronauts could choose to abort and fly back to orbit.
    Apollo 11 landing Side by side view of Apollo 11's descent - narrated by Neil Armstrong, 
     Shows the view out of the lunar module's window side by side with the broader panorama from google Moon, reconstructed from recent Lunar Reconnaissance Orbiter data.  Original side by side Video created by GoneToPlaid - news story about his video.

    The Apollo astronauts encountered several glitches during the landing, and finally landed with only seconds of fuel left. See also
    What went wrong on the Apollo 11 moon landing

    The Apollo crew could have aborted at any stage during this landing sequence and simply flown back into orbit again.

    In case of Mars, that's not feasible because you've lost so much energy through atmospheric friction.

    Escaping from Mars back to orbit again is only something you would do after you get there - with present day technology anyway - most likely using fuel you created on the surface of Mars from feedstock transported there earlier in a previous mission.

    Mars Direct - The Mars Society

    Mars direct idea to create fuel on the surface from hydrogen feedstock for the return journey - unlike Apollo you have to land on the surface first and refuel before you have a chance to escape back to orbit, 
    So you are committed to the atmosphere, but to an atmosphere that isn't capable of giving you a soft landing. It's no surprise that we have had so many hard landings on Mars.

    It's not for nothing that they called the Curiosity landing "seven minutes of terror".

    Seven Minutes of Terror: The Challenges of Getting to Mars

    If they are lucky, first few spacecraft might land there safely. But that doesn't mean it is safe. Might just be luck. For instance many space shuttles flew safely before each of the two disasters. 

    Columbia taking off on its final mission. The many successful missions before were no guarantee of success; it crashed on re-entry to Earth due to the foam blocks issue.

    Designing a human rated spacecraft to land safely on Mars is probably of similar order of complexity to designing the space shuttle.


    We have no experience at all of long term life support in space in a closed system. With the ISS they depend on sending tons of material to the habitat every few months - and disposing of tons of material also. They can't even wash their own clothes but just burn them up in the atmosphere and get clean clothes sent up to them again.

    Progress (spacecraft) - there are three or four flights per year, just to supply materials to the ISS. The spacecraft is then kept attached to the ISS, and filled with waste materials which burn up in the atmosphere when it is discarded.

    You can't have progress spacecraft continually supplying essential materials to interplanetary spacecraft in this way - and we have not yet tested a spacecraft able to maintain a crew in space for a year or more without continual resupply from Earth

    To go straight from the ISS to an interplanetary flight, even a first fly by as in the Inspiration Mars plans or the double Athena, is a huge leap, I don't think we are ready for that yet. First wet need to demonstrate in practice that whatever idea you have for long term life support is reliable, and can work for years on end. And test it  properly with humans on board for the duration of the test mission, and test it in space, not on the Earth.

    If we could do this on the ISS it would hugely reduce the costs of supporting the astronauts in space. If astronauts could be healthy for years on end in space also, you'd only need a mission to the ISS every year or two. That we haven't managed to do that yet shows how difficult the task is.

    I think the issues of long term life support are greatly underestimated by the optimists. It may be that there are simple ways to do it, e.g. algae for oxygen or whatever. But this needs to be demonstrated first.


    Colonists on Mars would be troglodytes. It's okay to live there for a year or two probably, if you don't mind an extra risk of 3% of cancer that would on average cut your life short by 15 years if you get it. But anyone living there long term would be limited to a couple of hours a day in the open in a spacesuit. That's also your limit, not just for spacesuits, but also, on travel in vehicles over the surface, and your time in greenhouses exposed to natural light, because the small amount of air in a greenhouse wouldn't provide much protection from the hugely penetrating cosmic radiation.

    This shows cosmic radiation damage of DNA. On the surface of Mars every cell will get hit many times by highly energetic cosmic rays, which on Earth are absorbed by our thick atmosphere and the magnetosphere. Mars has no thick atmosphere and almost no magnetic field.

    Most colonists would spend as much time indoors as possible. If you limit yourself to a couple of hours out of doors (including in vehicles) a day, that leaves you with a 3% extra risk of a cancer, as best as we can estimate it at present. Of those who die from cancer, on average their life expectancy will be reduced by 15 years (these figures have large error margins).

    It's like living on Earth immediately after a global nuclear war, worse probably, to try to live on Mars with the cosmic radiation.

    Most of your life you'd need to be protected by meters of regolith from the cosmic radiation.

    Fetus's and young children are especially vulnerable and young or pregnant wouldn't be permitted to go outside at all probably.


    The low gravity has unknown effects on human body. It might be that Martian gravity would stop your bones from growing and mean that you lose bone mass, just like for zero gravity. The optimists say that your body would develop normally on Mars and just have much weaker bones, whatever you need for the Martian environment. But we didn't evolve on Mars, and that's really hopeful thinking rather than good science I think. It might well be that young children for instance have no bone growth on Mars in their legs and arms and weight bearing parts of their body. It might be that it's impossible to give birth and for a fetus to grow normally in the Mars gravity.

    This is simply unknown at present, we need to know the answers before anyone contemplates long term residence in low g environments.


    If you want to build on Mars you need your buildings to be able to withstand tons per square meter of outwards pressure. You need to make all your oxygen from the water or similar sources. There's no way this is going to be as easy as living on Earth, it's going to be hugely expensive - or a massive amount of your time.

    Close up of the ISS, the modules have to be engineered to withstand ten tons per square meter outwards pressure, and windows especially are hard to make. You will never be able to build a normal house on Mars, in the next few centuries at least but have to build massively constructed structures like this, with few windows, just to contain the air.
    Yes could have domes for greenhouses on Mars - but they also have to be spherical or almost spherical in structure and made of strong materials able to withstand ten tons per square meter outward pressure.. You can't just build a lightweight greenhouse like you can on Earth, so living on Mars would always be hugely more difficult than living on the Earth at least with present day technology.

    And you depend on complex equipment to stay alive. Even spacesuits are pretty expensive items - and if you damage your spacesuit, probably you can't repair it, but are stranded in your habitat until someone can send you a repalcement.

    The environment regulation is hugely complicated - at least until we get to the point where you can have natural Biosphere 2 type atmosphere generation - a dozen or more different poisonous gases that can build up in a human habitat, in case of the ISS system. And this is going to be more complex than the ISS because the ISS depends on ability to vent gases into space and constant supply of oxygen from Earth, and is no way a closed system.

    It's really only a place that multi-billionaires could contemplate living long term - or ordinary people if massively subsidised to hundreds of millions of dollars per person.

    Yes perhaps as Elon Musk proposes, you could physically get people to Mars, land them there, for your $500,000, but could you keep them alive, and would they be alive when they get there, and how much would it cost long term to support them? 


    The biggest problem though is with the motivation behind it, that you go to Mars for a second home or to escape from Earth. There is no way that Mars is gong to be a second home in that sense. And terraforming is a thousand year long project even for the most optimistic, and others say it is more like a 100,000 year long project.

    That means - that you are doing it, not to solve problems in our present generation, but because you think our descendants 1000 years from now will appreciate what you are doing. But - they might not, what we do to Mars now might cause problems 1000 years from now if we do things that mess Mars up through carelessness.


    This is the biggy for me. There is no way we can send humans to Mars without greatly increasing the risk of introducing Earth life to the planet. 

    The easiest way to see that is, that if you have a hard landing on Mars, then the crashed spacecraft would be an immediate huge fail of our efforts under COSPAR to keep Mars clear of Earth life contamination. 

    Mars Polar lander - as it should have been, artist's impression. Sadly, it crashed during the landing, probably because of a program design error - the software didn't take account of vibrations caused when the legs deployed, although this was a known issue, and interpreted this as landing, and so cut off the engine too soon.

    It is a potential contamination risk for Mars. Hopefully some time as our technology matures, we can go back and recover the debris and either sterilize it or remove it from the Mars surface

    If humans crash on Mars similarly, it's a huge immediate fail of planetary protection. With dead bodies on the surface, together with their food, water, air, then there would be hundreds of trillions of microbes in tens of thousands of species - most unknown to science as only a tiny percentage of microbes have ever been characterized and studied - and the Martian dust storms could spread this to anywhere on the surface of Mars, and there are many microbes that we know can enter highly resistant dormant states - and that can also survive in Mars analog habitats and grow there, for some of the habitats we are almost certain exist on Mars.

    I'd say that the same also applies for humans on the surface, it's not feasible to land a biohazard containment laboratory on Mars with Earth microbes in the habitats as the biohazard to contain, and spacesuits leak air constantly through the joints. And the habitats can't possibly be totally closed system, will be various wastes that get vented, and if any humans die, their bodies won't be recycled in such small habitats, or kept permanently inside the habitats, I'm pretty sure.

    But the most obvious thing is the hard landing. There is simply no way around that on modern technology as far as I can see, human crash on Mars is an immediate fail. Which is especially important now, that we realize there probably are habitats on Mars for present day life, not just past life.

    That includes the warm seasonal flows discovered to exist even in equatorial regions last year - almost certainly flowing water or salty water, no alternative plausible explanation been published for them - surprising though that is. They form on sun facing slopes, in the spring through to autumn, get longer as it gets warmer, far too warm for dry ice, and wrong season for wind effects and no correlation with wind. Not been totally proved yet but it's almost impossible to imagine any other explanation working.

    Locations of Warm Seasonal Flows shown with black stars, some of them in the equatorial regions of Mars. These are believed to be signs of water flowing, due to the temperature range at which they form and location (not to be confused with the dry gulleys, which are a CO2 phenomenon). This is one of the most promising habitats for life on Mars, though there are other possibilities as well. See Water seems to flow freely on Mars (Nature article).

    Then the DLR experiments showing that lichens and cyanobacteria can survive and metabolize in the Mars like environment using just the night time humidity of the air, even when exposed to the UV in partially shaded locations.

    Then also the deliquescing salts possible habitat discovered by Phoenix - again not proved, but seems very likely, that in some places right mixtures of salts, that you get thin layers a few mms thick of liquid below the surface of the soil, that in some cases, life could inhabit. Plus solid state greenhouse effect could melt ice near the Martian geysers (though probably dry ice phenomenon, still could be melted ice there as well).

    So, there is plenty to contaminate. And the global dust storms able to take hardy spores imbedded in a grain of dust anywhere on Mars, protected also from UV by the iron oxides in the dust.

    Much of this is new research in just the last few years, especially the equatorial warm seasonal flows and the DLR results.


    Then there's also the growing realization of how much we could learn from Mars. We know so little about the early stages of evolution. According to one estimate there have been as many major steps of evolution between amino acids and the most primitive living cells we know as there have been between them and us - and we know nothing about how that happened and what those steps were.

    Here is a video animation of transcription and translation all the way from DNA through RNA to Haemoglobin (in this example)

    This shows how complex even the simplest cells we know are - this is just one stage of one of themany processes going on in every single living cell -a million chemicals in a complex dance. They couldn't have arisen by chance directly from amino acids. We have no idea how a primitive cell evolved from the basic amino acids.

    This diagram shows the complexity of the DNA as measured using the number of functional non redundant nucleotides

    This is  a better measure of the genetic complexity of the organism than the total length of its DNA. Some microbes have more DNA than a human being - much of that used for other purposes rather than for genetic coding, the so called C Value Enigma. Measuring it this way deals with that issue.

    Notice that the prokaryotes are well over half way between the amino acids and ourselves.
    And Mars had an ocean early on and could tell us much about this because unlike Earth, without continental drift, it almost certainly has deposits from those times, that are in pristine condition pretty much. But not near the surface now, because of cosmic radiation, at least the best deposits, probably a few meters down say 10 meters below surface and hard to find, though some may be more recently exposed again. 

    Same also for present day life, the habitats are rare and hard to study, unless there is life almost everywhere on Mars as in the DLR idea - if so we might find it early on - but if not -then it might take decades.

    So - we need to give ourselves time to search for this properly.

    And the instruments we use are sensitive to just a single amino acid in a gram of soil, say, or able to detect a single DNA molecule. They'd be hugely confused by contamination by Earth life.

    Raman spectrometer able to do highly sensitive non destructive analysis able to detect molecular structure -one of the Exomars instruments
    Field testing of the Exomars Raman spectrometer

    These instruments are so sensitive they'd be hugely confused by any contamination of Mars by Earth life and give ambiguous results.

    And - Robert Zubrin argued that we'd easily be able to separate out Earth life contamination from Mars life but that's not true. 

    First of all, of course you'd not be able to detect life on Mars any more by simple detection of chirality or biosignatures because that wouldn't distinguish Mars from Earth life, so would set back our understanding of Mars tremendously, make it vastly more complex.

    Then, especially for the archaea, then many entire phyla of archaea are simply unknown. This is the problem of microbial dark matter

    We know they exist, through indirect evidence, but haven''t e.g. DNA sequenced them and can't cultivate them and don't know anything about them, how they live, what they do etc. And most microbes have not been DNA sequenced even of the well studied ones.

    see How Many Microbes Are Hiding Among Us?, and Bringing Microbial Dark Matter Into the Light


    Well - we don't need to give up on the whole idea. It's landing humans on the surface that's the big issue.

    But - we can have humans living in orbit around Mars - no problem so long as really careful. E..g. wouldn't use aerobraking. 

    But you can get into a highly elliptical Mars capture orbit - very useful for colonies and for studying the planet - for less delta v than the surface of the Moon. It's a sun precessing Molniya orbit, comes in close over the surface of Mars twice a day, on sunny side, on opposite sides of Mars. A spectacular orbit to live in with Mars continually changing size in the sky and a close fly-by twice a day.

    And  gives control of robots on the surface with near real time tele-presence on opposite sides of Mars every day. With that, you could drive e.g. Curiosity at tens of kilometers per hour over the surface. Rapidly explore large areas of Mars.
    I'd do it using all the same technology as for Mars surface  - making fuel for your vehicles on the surface from the atmosphere + hydrogen feed stock - and thin film solar panels for lots of power for low amounts of weight lifted from Earth - all that stuff - but with the astronauts operating them from orbit.

    And use the ideas for human habitas in orbit. Safer anyway - humans don't need to do the dangerous descent to Mars - and it's just the rovers on the surface that do that. And they can explore areas on Mars that would be far too dangerous for a human in a spacesuit. And - admittedly telepresence so far is not quite as agile and mobile as humans on the surface - but neither are spacesuits - and not clear at all that spacesuits do better than telerobots.

    Even a few years back, the HERRO mission study came up with the conclusion that humans in orbit doing science by telepresence could do as much science as three similar missions on the surface, for a lower cost, less danger to humans - and of course - much reduced risk of contaminating Mars.

    The 2013 Telerobotics Symposium explored ways of studying Mars by telerobotics.


    But I don't think it's safe to do an interplanetary mission at all right now. We should do a precursor mission to far side of the Moon. And not just a few days fly by. Instead - send astronauts to the L2 position for several years - WITH NO RESUPPLY FROM THE EARTH - and see if they can last out. If not, then we shouldn't do interplanetary missions until we sort out the problems making it unsafe for humans to spend several years at a time in L2. 

    And if it works, then it means we could have continual human presence at L2 for far lower cost than the ISS - it's all the supply missions to he ISS and need to change the crew every few months that make it so expensive to maintain.

    The Moon also is of immense interest to study - to scientists at least. Those who don't find the Moon interesting because it's "already been done" would find Mars just as uninteresting a few years after it has "been done".

    After a several years long precursoor to L2 - and lots for them to do - exploring far side of Moon + poles via telepresence - and building long wave radio telescopes on the far side - and searching for traces of meteorites from early Earth on the lunar surface and exploring caves and geology of the Moon - and testing the telerobotics needed to make all that possible - it would be a really interesting mission for the astronauts involved. 

    It's like this NASA concept NASA Eyes Plan for Deep-Space Outpost Near the Moon

    This shows how astronauts would control rovers on the surface of the Moon by telerobotics

    Robotic roll-out of an antenna — part of a low-frequency array of radio antennas to observe the first stars in the early universe.

    While doing this, they'd also be testing artificial gravity + whatever else they use to mitigate the effects of cosmic radiation. Would be a really interesting mission for those who are interested in such things, and those who aren't - I think would in practice soon get totally bored by a mission to Mars anyway. It would be a bit like a mission to Antarctica - interesting to start with - but if you haven't got a lot of scientific interest or some other reason to be there - then you'd soon get tired of the cold, and the long nights.

    So after several years of that, once we are sure we can reliably send a spacecraft away from Earth for years at a time safely - then could send humans to Mars orbit. 

    But not right away. I think thats' unwise and unsafe. And to the surface - even more so - that's making an irreversible decision to contaminate Mars - and the colonists simply don't have legal or moral right to do that for the rest of us. 


    This idea that perhaps we shouldn't send humans to the surface of Mars because we'd contaminate it with Earth life is not much mentioned in the news. Out of dozens of news stories about ideas for human missions to Mars, perhaps only one or two will ever even mention it as an issue.

    But it's frequently mentioned in the academic literature on spaceflight, with many publications debating the issue, and several planetary protection workshops on human missions to Mars. It's just that their deliberations rarely get into the news.

    Here is a quote from "When Bioshperes Collide":

    "One of the most reliable ways to reduce the risk of forward contamination during visits to extraterrestrial bodies is to make those visits only with robotic spacecraft. Sending a person to Mars would be, for some observers, more exciting. But in the view of much of the space science community, robotic missions are the way to accomplish the maximum amount of scientific inquiry since valuable fuel and shipboard power do not have to be expended in transporting and operating the equipment to keep a human crew alive and healthy. And very important to planetary protection goals, robotic craft can be thoroughly sterilized, while humans cannot. Such a difference can be critical in protecting sensitive targets, such as the special regions of Mars, from forward contamination.

    Perhaps a change in the public's perspective as to just what today's robotic missions really are would be helpful in deciding what types of missions are important to implement. In the opinion of Terence Johnson, who has played a major role in many of NASA's robotic missions, including serving as the project scientist for the Galileo mission and the planned Europa Orbiter mission, the term "robotic exploration" misses the point. NASA is actually conducting human exploration on these projects.  The mission crews that sit in the control panel at JPL, "as well as everyone else who can log on to the Internet" can observe in near real-time what is going on. The spacecraft instruments, in other words, are becoming more like collective sense organs for humankind. Thus, according to Johnson, when NASA conducts it's so-called robotic missions, people all around the world are really "all standing on the bridge of Starship Enterprise". The question must thus be asked, when, if ever, is it necessary for the good of humankind to send people rather than increasingly sophisticated robots to explore other worlds"

    See When Biospheres Collide


    Much more about all this on my Science20 column, see

    Robert Walker's blog

    First of all, a common argument for going to colonize Mars is to find a second home for humanity. But, if you look at it carefully, there is no way that Mars is going to be a good place to shelter from any likely catastrophe, in the next few centuries anyway even with most optimistic ideas for terraforming.

    Then,if you did survive, then after any even remotely likely disaster, the most habitable place in the solar system, the easiest place to restore and terraform after the disaster, would still be the Earth. So the best thing you could do is get back to Earth as quickly as you can. So no great benefit, just a nuisance, to be on Mars so far from the best place in the solar system to be to help with recovery of humanity.

    More about that in this article: No Escape From Problems in Space Colonies - Earth is  Des Res - Even After Nuclear War or Asteroid Impact

    Many more articles covering different aspects of these various questions, including:

    Let's Plan For Exploration and Discovery of Space with no End Date - NOT Escape from Earth - Opinion Piece

    Where Should we Send our Rovers to Mars to Unravel Mystery of Origin of First Living Cells?

    Our Spacecraft Could Look Straight At an Extraterrestrial Microbe - And Not See a Thing!

    Rhythms From Martian Sands - What Did Our Viking Landers Find in 1976? Astonishingly, We Don't Know

    Why Mars is NOT a Great Place to Live - Amazing to Explore From Orbit  - with RC Rovers, and Nature Inspired Avatars

    To Terraform Mars with Present Technology - Far into Realms of Magical Thinking - Opinion Piece

    Trouble With Terraforming Mars

    "Ten Reasons Not To Live On Mars, Great Place To Explore" - On The Space Show

    Ten Reasons NOT To Live On Mars - Great Place To Explore

    The article you are reading right now is my answer to a question on Quora - and thought I'd put it here as well. Of course, I've covered most of this already in my other posts here, but this I think gave a slightly different interestng slant on it all.

    For other answers, and so other points of view on it, see the original Quora question

    How feasible is Elon Musk's idea to establish a colony on Mars in the 2020s?


    Colonizing Mars will be like colonizing the new world. When the English came to James Town at least they had water, and local people who were willing to help them more than hurt them. Even so the fatality rate was 90%. On Mars there would not even be that imagine the mortality rate.
    Science advances as much by mistakes as by plans.
    Yes I can imagine pretty huge!
    Another example is, the attempt by the Vikings to colonize N. America at L'Anse aux Meadows

    I don't think they are too sure about what happened in detail, but it failed as an attempt to set up a permanent settlement, they were only there for a year or two. Later Vikings gave up on the idea of colonizing America and instead got involved in trading with them instead. And the Vikings were hardy, adventurous, brave people, who didn't often give up on projects they wanted to accomplish.

    I think that similarly - if they ever did try to colonize Mars in 2020s - which I hope not for the reasons given - and also thing would not be permitted by international law -  that it would be pretty much like the Moon. Great excitement to start with, but within a few years, general public loses interest, those who are responsible for the finance, get voted out or lose influence, or just run out of money, and the whole thing folds up, just like the Viking attempt on N. America.

    Then, maybe a few centuries later it might be feasible to do it, if we still want to, and if there is some good reason to do it, and have a pretty clear idea of what the long term results woudl be, and depending on what we discover about Mars itself in the interim.
    You're right about that.  Right now we want to go cheap just so that we can say we've been there.  
    What is needed is to send a army of robotic construction machines ahead of any humans to use materials there to build out infrastructure.  You know a base with prepared landing pads, space for habitats already dug in, and a rudimentary system to guide them into the landing.  Systems in place to produce water, and fuel from available Martian materials.  We could make sure it's all in place and functional before anyone has to get on a rocket and go there. 

    In my humble opinion there is one reason we won't do that.  As has been said people want to relive the moon landing.  So we will do it for the least money possible, and send humans on the first mission to establish a colony. 
    Science advances as much by mistakes as by plans.
    Yes, and two years later there is an almost total loss of interest in the general public, and when Martian colonists are mentioned everyone yawns, apart from occasional news stories such as the first time someone hits a golf ball on Mars - if you take the Moon landings as a precedent. 

    But the difference from the Moon is that colonizing Mars has consequences. Especially if you then get Earth life from the colony gradually spreading over the planet - maybe even making visible changes in its appearance from Earth. Or just -that you get life discovered on Mars, either by the colonists or a later expedition - but nobody knows if it is contamination from the colony or was always there, and it takes ages to disentangle. Or you find things like the Martian nanobes - but nobody knows if they are life or not, because though there are biosignatures, those could easily be caused by contamination from Earth. 

    Then - unlike the Moon where there were no consequences on later study of the Moon, was only positive, in the case of Mars, then you'd get a pretty negative idea of the effect of the first colonists  on Mars when you look back at it just a few years later and people might then wonder how they could have been so stupid as to do what they did. That is if Mars turns out to be as biologically interesting as I think it might be. They might seem like the people who, with good intentions, introduced rabbits to Australia.
    Saying: "The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting."
    Now of course they are a major nuisance in Australia.

    At any rate - it wouldn't be permitted under the Outer Space Treaty - I don't see how it is - and nobody has worked out a road map to get from exploration phase to permitting contamination of Mars by humans. So personally - I think that what will happen is that when they get to the stage of trying to work out the details - that they'll just find they can't pass planetary protection certification of their missions. And would get objections from scientists in other countries and from the COSPAR workshops - when the time actually comes. Hope so anyway.

    If you aren't worried about contaminating Mars, then what you suggest would help - but wouldn't make it safe for humans - at least - no more safe than the space shuttle was, probably less safe considering how hazardous landings on Mars are - and it remains a hugely expensive project, with no real return, or benefit over orbital colonies.

    While with humans in orbit around Mars, and never able to land there, only explore telerobotically - well there is something fascinating about anything that is unattainable like that. I think that would actually increase the long term interest in exploring Mars.
    And we've seen with Curiosity, and Opportunity and Spirit and Pathfinder how much interest the general public has in robotic exploration of Mars on the surface. I think telerobotic exploration, operated by humans in orbit, in real time, with real time HD streaming of everythign they do on Mars back to Earth would also be really interesting - in a genuine way. NOt just big brother type streaming of snoring astronauts in habitats  - but real time exciting exploration of places on Mars that you could never send humans to, because it's too dangerous, or because you need lightweight flying machines to do it at reasonable cost - or because they are sensitive areas that humans would contaminate.  And simultaneous exploration of many places on Mars for the same cost because it costs far less to land a rover on Mars than to land a human party + a vehicle they can drive around on the surface at the same speed. So can land several of them for the price of just one human rated one.

    I hope to help inspire by writing about these ideas and helping people to see the value in this way of exploring Mars, which so far mainly only the academics and scientists have discussed. And it is possible for public opinion on things to change, I've seen many huge changes in generally accepted views in society in a wide range of topics during my lifetime.

    Oh and the first orbital mission would cost quite a bit less than a landing on the surface.
    Michael Martinez
    I don't have a problem with restricting contamination of the Martian biosphere for now because we don't yet have the technology to live there.  But at some point you have to stop protecting the alien environment and decide that, yes, you are going to colonize the world.
    Sagan said that "Mars belongs to the Martians even if they are only microbes".  Well, life on Earth doesn't work that way and if we're seriously going to venture out into the universe then we have to get over these concerns about not influencing other biospheres.  They will influence us as well.  It may not always be pretty but it will be the next step for us.

    I like your ideas about building space habitats before we try to colonize any planets.  I think we can learn many useful lessons from building the habitats first.  But someday we're going to terraform our first planet.  When that day comes it will have been a great disservice to life in general if humanity is divided on the issue because the only inevitable consequence of such a division in thought and purpose would be war.

    When we leave Earth let's hope we can leave war behind.
    Why though, why do you feel that we have to colonize Mars? Do you feel we have to colonize the sea bed for instance? Or that we have to colonize the heart of the Atacama desert, or the Greenland ice sheet? Or build houses on all the slopes and summits of all the mountains in the Himalayas?

    If not, then why do we have to build houses on Mars? Which is far more inhospitable than any of those places? And when it might be of great value left pristine?

    None of those places require us to make oxygen fpr the air we breath from water or to contain atmosphere with tons per square meter, or cover our houses with meters of soil to protect from cosmic radiation. 

    It depends on what we discover on Mars. That's why I feel we can't actually do this discussion properly quite yet. But one possibility is that Mars turns out to have answers to many questions about the origin of life on Earth. Another possibility is that Mars has XNA based life, different basis from Earth life.

    Especially if it has interestingly different life, then several people, in published papers, have suggested that we should either keep it pristine, or else, in the case of Chris McKay's papers, he argues that if Mars does have present day life, that we should reverse all the contamination by Earth life that we've done so far, and then instead of terraforming Mars, do what we can to make Mars an ideal place for the native Martian life - which quite possibly might not like the same things that Earth life does.

    I hope it won't mean war of course. But civilized discussion. And - needs to be done once we understand what Mars is like much better. And our situation on Earth would probably be different also, and we'd also have gained a great deal from study of exoplanets - and maybe even detected signs of life around other planets - or if not - maybe found that life is very rare and not yet detected around exoplanets. And we might have started to learn new things about life from Mars, and have some inkling, perhaps, of where those discoveries are headed.

    We can't know any of that right now though, only speculate. So, same as Chris McKay has argued many times, I feel that our exploration of the solar system should be biologically reversible, that we don't introduce life to any part of the solar system where it can take hold and never be removed again - until we have a hugely clearer idea of the nature of the solar system - and what we want to do, if anything, to change it.

    Certainly you won't get me to agree that we must terraform Mars eventually :). Or many of the authors who have written on this subject in the published literature. So the best you can hope for is a civilized discussion of this when the time comes. Though people may change their ideas, in any direction, depending on what we discover as we continue to explore Mars.
    Myself - well prerequisites for even contemplating terraforming Mars or introducing Earth life there:

    •  if it turned out that Mars has no present day life, or it is very similar to Earth life
    • if we can do simulations of introductions of Earth life to Mars and somehow prove pretty conclusively that it is not going to have harmful effects on the Mars environment that we might later regret
    • if we can show it doesn't matter in what order we introduce the lifeforms, or if it does matter, have worked out how we are going to introduce life to the planet in the correct sequence.
    • if there is some point in it - not just doing it because Mars is there and we want to have the bragging rights to say that humans have set foot on the planet
    • if we have explored Mars thoroughly to the extent that we feel we've learnt as much as we need to from Pristine Mars and shown beyond reasonable doubt that we can do the rest of the scientific study adequately with a contaminated Mars
    • if we have a reasonable idea of what would happen to Mars not just in the next decade or so, but far into the future, that it's not going to damage it's value for our descendants (who are the ones who it will be most useful to, not really much use to us at present really as far as I can see)
    Then - perhaps I could be persuaded. But the last one is the hardest - I feel myself that it is even immoral to terraform Mars if you know that it is going to unterraform pretty quickly.

    For instance suppose it takes 1000 years to terraform as the optimists suggeest. If so that meas that Mars is pretty easy to change - suggests to me - that it could also unterraform just as quickly, maybe 1000 years later, through unexpected feedback loops, perhaps involving life cycles, so you just get a few centuries of Earth like habitat there. You have to prove that's not going to happen - and not going to end up in some dreadful end state maybe with high levels of poisonous gases in the atmosphere or with microbes and other life forms hazardous to humans predominating in the environment.

    And - I think that by far the most interesting outcome, the one to hope for, is that Mars does turn out to have present day life, and not just similar to Earth life, but interestingly different. Because if that is what the situation is, we are so amazingly lucky. We then have an exoplanet on our very doorstep - which maybe most space faring civilizations would need to travel light years to find. So we should treasure it in that situation, especially one that started so Earth like in its early solar system.
    There is one thing that having a human colony on Mars would provide us with that none of those places would.   Redundancy should some catastrophe befall Earth.  
    Once a colony on Mars was self sustaining, it would be an oasis of human and other Earth life in the event that Earth was subject to an unavoidable collision with a large comet or asteroid, or Nuclear war. 
    Science advances as much by mistakes as by plans.
    Oh, sorry, I should say something about that.
    I wrote an article on just that point here:

    No Escape From Problems in Space Colonies - Earth is Des Res - Even After Nuclear War or Asteroid Impact

    The thing is - that Mars doesn't really do that. Because even immediately after an asteroid impact, still Earth is far more habitable than Mars is. And even if Mars did turn out to be teraformable, then it's not going to be as habitable as Earth after an asteroid impact in anything less than a thousand years and most likely 100,000 years.

    So - if there was anyone on Mars and then we had an asteroid impact like that, the very best thing they could do to help with continuation of the human species is to come back to Earth and help with rebuilding after the impact. Earth would still remain by far the most easily terraformable planet in the solar system after such a disaster.

    Also you don't need to be on Mars to escape the worst of the effect. Just the other side of the Earth in most cases, and the worst ones still would be survived by anyone who  is deep underground or beneath the sea - and if you are really worried about surviving asteroid impacts, would be far easier to set up some kind of permanent underground base somewhere, , or rather two of them on opposite sides of he world in remote chance one gets hit. That would cost only a tiny fraction of the cost of a similar base on Mars, and also means you are right here, on the spot ready to start rebuilding Earth immediately after the disaster. Not trapped on Mars, probably unable to return, or do anything except look on helplessly from a distance as Earth civilization falls apart (and your supplies from Earth stop coming).
    Those are all great rebuttals to the argument that Mars could serve as a last redoubt of mankind and Earth life. 
    Science advances as much by mistakes as by plans.
    Thanks :). Glad it helps. Yes those arguments are so frequently and strongly argued in the media especially by Robert Zubrin and the like, in vivid clever and witty ways - I think it's about time someone made a clear case for the opposite point of view :). Hope to help a bit there, by writing about it, people say I write well and have good style, so that's one area where I can help, by talking about these things here, and making use of the things I can do.
    Which leves us with the pure scientific interest in going to Mars and exploring places which Robots cannot.  Perhaps having a human biologist or two there could settle the debate on Martian life once and for all. 
    Science advances as much by mistakes as by plans.
    Michael Martinez
    Why did we have to colonize any part of Earth?  Weren't we particularly happy living in Africa?  It is in our nature to expand and grow.  To arbitrarily stop here doesn't make any sense.  Life competes and expands and seeks out new opportunities.
    It is no more unnatural for man to build cities than for ants to build supercolonies, bees to build hives, and termites to build supercommunities of mounds.  So why is it suddenly wrong or unnatural for life to spread from one planet to another?

    We already have debates about whether life came here from the stars; whether Martian microbes arrived here in meteorites millions of years ago; even about whether alien spaceships are roaming our skies.  If we can embrace the idea of life traveling from planet to planet, then there is no logical reason to draw a line and say, "We'll go no further."

    I'm not saying I want to burst out of the Solar System and start conquering alien civilizations, but neither do I want us to remain Earthbound simply because life might exist elsewhere.  Let's go meet it, embrace it, and learn about it.  If it's out there the odds are pretty good that sooner or later it will come here, maybe more than once.

    We might as well insist that we not irrigate deserts when we get hungry enough, or that we not plant forests when the CO2 is overwhelming, because we might disturb a fragile ecosystem somewhere.  We disturb ecosystems simply by breathing, eating, and building shelter for ourselves.

    I want us to be able to travel through the galaxy.  Sure, I'd love not to destroy whole ecosystems for the sake of being a galactic tourist; but I don't want to treat every planet as a finished product.  We have a place in the universe and that place may well change in many ways.  I see no reason not to accept the challenge of moving our ecosystem into space.

    I'm not worried that life will end quickly (again); I'd just like to see us get off this rock because, frankly, I have grown up in a culture that dreams of space travel.  It is infused into my imagination and my yearnings so completely that I can't imagine NOT venturing out into the universe, terraforming planets, and building interstellar empires.

    If life exists elsewhere in the universe, in our galaxy, then if we don't move beyond the limits of our native star system someone else will move beyond theirs and for all we know they won't have any ethical qualms about wiping the slate clean here.  I'd rather for our ecosystem's sake meet them halfway on relatively equal terms, if that is possible.

    Show me a thinking, feeling Martian even at a level comparable to that of ants and other social insects and I'll agree that maybe we should not try to plant our flag there.  But microbes that have failed to become even insects in 4 billion years probably don't have much chance of achieving anything significant in the next 1 billion years.
    Right - the thing is - with Mars - that it's the knowledge we gain from Mars, the scientific interest -that's the main reason for protecting it from Earth life. At least that's how the Outer Space Treaty is interpreted and the motivation behind all our planetary protection measures so far.
    So - the thing is we want to know how life evolved and fill in that huge gap in our understanding, and it seems that most likely we can't do that, or it will be much harder, if Mars gets contaminated.

    So - that way - it doesn't matter how complex or simple Martian life is - if it exists at all - or if there was life there in the past, or also even if there never was life on Mars, all of these are immensely interesting. If there never was life on Mars, still it had a whole sea with organics - and even in laboratories you get complex things going on - so what does happen to a sea with organics, energy, nitrates etc when left for several hundred million years? Does it evolve life, and how easy is it for that to happen?
    Actually there could be multi-cellular life on Mars. Could be plant life. Could even be some types of animal life also. Either in caves, or even on the surface, we'd not be able to detect lichens, for instance, from orbit, or tiny animals, such as for instance ones like tardigrades, microscopic or tiny multicellular creatures - there are anaerobic animals (just a few mms in scale but multicellular and not plants), rare but do exist, so they could also exist on Mars too.


    As for venturing into space - well the thing is, I think we should focus on adventure and exploration - rather than colonizing space. 

    That's much more interesting - and more likely to have sustained interest long term also.

    Certainly not trying to put a stop on venturing into space. Just a wake up call to be realistic about why we are doing it and to recognize that it's not going to be as easy to live in the space environment, as humans, as it is on Earth.

    That we go there to explore, not to colonize, in the near future anyway. And if you are going to explore, then you will want to protect the most interesting things you could explore there, particularly will want to protect Mars from contamination as that's the very thing that makes it one of the most interesting places to explore in our solar system. And telerobotic exploration, in the modern age, is just as adequate as boots on the ground if your main aim is what you can hope to find out there by exploring.


    Now if your main aim is to live outside of Earth - well I think by far the beset way is to use free flying space colonies, using materials from the asteroids.

    The thing is - wherever you go - apart from the Venus cloud tops - which I think also is another possibility in not to distant future if planetary protection considerations permit - then you need protection from cosmic radiation.

    If you are on a planet, there isn't much choice there, except to live a fairly troglodyte type existence most of your life in habitats beneath meters of soil.

    But if you make a free habitat like the Stanford Torus or O'Neil cylinder - then you can build huge open spaces in space - with the shielding all around it. You couldn't build something like an O'Neil cylinder on a planet. So you can't build those huge spaces with vast vistas on planetary surfaces - at least not easily.

    You get natural sunlight then by deflecting the light from the sun into your habitat with giant mirrors. Again you could do that on a planetary surface or the Moon also - but easier to do in space. And then you have no contamination issues either to worry about.

    I don't think it can possibly be as easy to build such a habitat as it is to build houses on the Earth - but once you have the infrastructure of the whole thing set up - then you can build houses inside it, just using normal construction methods. So again - I think in the long term, these big space projects would be a cheaper way of providing houses in space than anything you get on planetary surfaces - or Moons - except to try to duplicate the same ideas with mega-constructions on the surfaces.

    And - you can build them so that the environment inside is whatever you want, e.g. passively heated, tropical environment. And the main issue in space is to make sure you can radiate enough heat away, not keeping it warm, as space is a good insulator.

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

    The only exception there really is Venus. At the Venus cloud tops, you could live in a shirt sleeves environment, without any cosmic radiation shielding, and it's also far easier to build houses also. It's the only place in the inner solar system where houses don't have to be massively engineered to withstand ten tons per square meter of outward pressure - and they don't need cosmic radiation shielding either. 

    For Venus, see my 
    Will We Build Colonies That Float Over Venus Like Buckminster Fuller's "Cloud Nine"?

    but with the caveat
    If there is Life in Venus Cloud Tops - Do we Need to Protect Earth - or Venus - Could Returned XNA mean Goodbye DNA for Instance?


    As for the idea that we should colonize the galaxy first, before anyone else does - well civilizations arising in galaxies - either they are very common and our galaxy is already filled with civilizations - but if not, if they are rare - then this is something that only happens every fe w hundred million or billion years. And surely hasn't happened yet as a species like us, if we set out to colonize the galaxy without any restrictions, then you'd end up eventually with humans on every planet in the galaxy that's at all habitable.

    So since there are no ETs already living in our solar system, and nobody has taken over the Earth before we evolved, can be pretty sure that we are the first species in our galaxy to do this. That is if we do try to colonize.

    But it might be that all species with enough wisdom decide not to colonize for the reasons I gave - and that those who don't have enough wisdom to make that decision are so reckless by nature that they destroy themselves.

    If that hypothesis is true then our galaxy might have many intelligent species - but none of them choose to colonize because it's too risky for themselves.

    Just an idea but I've not yet found any convincing argument to show that it is safe to colonize the galaxy, that it wouldn't be hazardous for us in the way described, either descendants with powerful planet and star busting technology - or self replicating machines they create, things that just get out of hand and create a paperclip event horizon type catastrophe, causing havoc in the galaxy.

    And - I don't really see any comfort in the outcome myself, if the galaxy is trashed by descendants of us rather than descendants of some other species.

    If anyone has a way to show it is safe, or a way to guarantee it to be reasonably safe, do share it!

    All this becomes particularly acute with free floating colonies because if they colonize the Oort cloud, then there isn't much to stop them from colonizing the entire galaxy just as a natural wave of colonization, from one Oort cloud to another as probably the clouds from adjacent stars mingle.

    I don't know what the solution is, but think it's an important thing to discuss, and see if anyone has any ideas about it, or solutions, or if anyone has a clear idea of what if anything we can do about it.

    Exploring the galaxy though - if that becomes easy - without colonizing - is no problem there.

    So in other words a Star Ship Enterprise style voyaging through the galaxy would be fine. It's when you start to build colonies wherever you go that you would get this issue - what happens to those colonies and what they do to the galaxy a few centuries into the future, and is it a safe thing to do that?
    Michael Martinez
    And we also need to know how to terraform planets.  Again, it's going to happen sooner or later.  I am on the side of doing it later because we clearly don't yet know how to do it.
    But there is no moral dilemma for life.  Life simply does what it does.

    I am not one of the people who wants to go to Mars.  I think that would be a terrible place to live and to die.  But I don't agree with the point of view that we should refrain from contaminating it.  We have already contaminated it by sending materials there that -- if life exists on the planet -- might alter the ecosystem.

    You cannot interact with an ecosystem without altering it and we have already made our mark there.  For all we know we introduced some compound to the planet that has caused a virulent and deadly outbreak of microbial disease and the biosphere is already dead.

    Science is not all about understanding where life comes from.  It is also about where life can go.  We need to strike a balance between those two goals while being realistic about what is within our present capabilities.

    So, again, I don't favor trying to colonize Mars right now.  But I do favor trying to make it more habitable for Earth life in the future.
    It's possible we might have contaminated Mars, yes. We've certainly sent viable life to Mars, but most think they are just sitting on our spacecraft in dormant states not doing anything. Mainly because conditions on Mars are so very harsh - and few life forms could live there - and it has to be the right life form in the right place to survive.
    Typically our spacecraft have 300,000 cultivable spores on launch, possibly a 100 times that of non cultivable spores. But that gets greatly reduced by the ultra violet radiation and cosmic radiation during the journey to Mars - and on Mars gets further reduced by the conditions there. 

    So - we haven't sent that many actual viable microbes to Mars. And then of all the species we might possibly have sent to Mars, then very few of them would be able to make much of the martian environment and reproduce there.

    So - there is a reasonable chance that we haven't contaminated it yet. Can only be probabilistic since that's the way all current protection measures work  to reduce the probability of contaminating Mars to be as low as possible, since, with current technology at least, we can't send rovers to Mars with totally zero probability of contaminating it.

    Then -  some day down the road we may need to reverse that contamination - that's Chris McKay's idea of biologically reversible exploration.

    Our rovers themselves though - or the landers - the actual materials they are made of - that's not a significant impact on a planet by itself on a land area as large as the land area of the Earth. It's microbes that can replicate that are the major issue.

    But when you say - that we must spread and contaminate Mars - because that's what life does - well life in the form of microbes can't build spaceships, nothing can except us humans on this planet. And just as we have risen above the capabilities of other life forms technologically - so also we have the capability of making decisions and taking responsibility for our actions.

    So, no, we don't have to contaminate Mars just because "that is what life does". That's our decision whether we do that or not, and we will have to live with the consequences either way.

    We have lots of rules and regulations to prevent spreading life on Earth - such as quarantine rules - and the rule that visitors to Antarctica have to clean their boots and do whatever they can to prevent spread of species from outside of Antarctica to the continent. So - it's not an "anything goes, life spreads wherever it can" world that we live in, and we can, it's totally realistic, develop rules and restrictions for Mars and space colonization.

    Indeed I don't think space colonization is going to be safe if there aren't rules to regulate it in one way or another. We've made a good start there with the Outer Space Treaty. And need to build on that. I'm not one of those who think that a "wild west" type attitude in space is a good idea or likely to be helpful in the future. I can only see disaster, with the fragile habitats, so easily destroyed, and the immense amount of energy in interplanetary spacecraft, if we have a lawless environment in space.

    Michael Martinez
    Spaceships may not be the only way to travel between planets.  We are limited by the scope of our imagination more than we are by the laws of physics.
    I think life will spread planet to planet, star to star, maybe even galaxy to galaxy.  It will do so in ways we argue against, cannot prove, and don't expect.

    But to distinguish between the microbes that may somehow cross space and us, and suggest that we have a moral obligation not to interfere with life on other planets, misses the point.  If there is life out there it's going to interact world-to-world, star-to-star, and maybe galaxy-to-galaxy.

    The longer we choose to remain isolated from the rest of life that may be out there the greater the chance that it will consume us (or whatever succeeds us on Earth if we don't last that long).

    The ethical choices we make should first and foremost be designed to protect us from our own bad choices, not to preserve something that we can't yet see or understand.

    Science fails if it assumes that every loss is a complete loss.  We can't study everything.  We can only study what we can get to, see, and measure.  Things have come and gone in the time you and I have debated these points -- things that our science will never study, although someone has seen them (such as a rain drop falling on the street).

    We cannot count the things we have missed but we can count the opportunities we have.  Unless we find a viable biosphere on Mars, one that has the potential to achieve something biologically, we don't owe it to the Martians to stay out of their backyard.  They have had 4 billion years to figure out a way to thrive.  Another 1 billion probably won't make much difference.
    I think you are talking about a different issue here. I.e. whether we should keep Mars pristine in case more highly evolved Martians arise there later on in its evolutionary history and haven't done so yet.
    I'd agree that doesn't seem too likely to happen - though who knows. What I think might happen, if we leave Mars alone for the next billion years, is that it might become briefly habitable when the sun warms up as it goes into its red giant phase. At that point it could be an oasis for whatever life there is on Earth at that time, if it has spaceflight capability. 

    Or maybe indeed higher life forms could evolve on Mars. Who knows.

    But whatever - that's a separate issue. And over a longer timescale. So for instance, a century from now, say, maybe even earlier, if we have really vigorous exploration of Mars via telepresence, we may have a thorough understanding of what life there is there if any, found out much about what life was like there in the early solar system, and so on.

    At that point - the idea that we need to keep Mars pristine for scientific study of its past and its present day life might then not be so strong as it is now, because we already have studied it extensively. Still - for instance we have studied Antarctica for decades now and people continue to make new discoveries there and no sign of the stream of discoveries drying up in biology. May be the same for Mars. And we do take great care to keep Antarctica pristine still - and especially so for the under the ice lakes - take enormous care not to contaminate those before we can study them. Mars, as far more interesting than those, especially if it has life, we'd surely want to take even more care.

    So, it might still be strong as a motivation even for centuries into the future.

    As for natural transport of life from one planet to another - yes that may well happen. But only a few selected species would ever make it - most species that could get to Mars in a human habitat would have no chance of getting there on a meteorite  and far easier to happen in the early solar system than now. And most meteorites take hundreds of thousands or millions of years to cross interplanetary space and are thoroughly sterilized by cosmic radiation when they get there. So not as easy as it is sometimes made out to be, to do that.

    Yet may happen. Nobody of course has proved it does happen. but is possible for instance, even that life on Earth comes from an earlier star system. 

    But I'm not saying life shouldn't spread from one star system to another :). Who could possibly say that? But that we should be careful about colonizing - planets - and also the galaxy - deliberate choices we can make., and a far faster process, and involving transport of complex multicellular and fragile creatures such as ourselves that would never get transferred from planet to planet via meteorite impacts (despite the Jules Verne story where a group of scientists get whisked off the Earth into interplanetary space on a comet, and survive the experience and return to Earth no worse for their journey :) ).

    I'm not saying anything about owing anything to Martians or prospective Martians. But rather that we shouldn't cheat ourselves of the valuable insights and discoveries we can gain from Mars in its pristine state.

    Your argument about Martians though does apply to colonizing the galaxy - do we have the right for instance to settle on Earth like worlds in the galaxy which could perhaps evolve other intelligent species if we don't do it. Most might say we do have that right. But if so - do you then say that extra terrestrials if they had the opportunity to do so, should have colonized Earth before we evolved here? When you put it that way around, I think most people would say that they don't have that right. But it is exactly the same situation really, just a matter of who you call the ET. To them, we would be the ETs.

    I think that also is a valid argument for colonization - it's a sepraate one from the one about whether we risk harming ourselves by colonizing the galaxy. The harm to ourselves is kind of more obvious and immediate - but I think the other one is important also.

    But not sure if that sort of an argument applies ot Mars - that depends on how likely it is that an ET could evolve on Mars if left undisturbed, and, as you say, I also think but of course not with any great certainty about it, that perhaps it's not that likely to happen.

    On the other hand, if Mars has interestingly different XNA based life on it, for instance, and we "Marsform" it to be best suited for that XNA rather than Earth life - then the question could come up quite acutely again - would intelligent ETs evolve on Mars.

    It also comes up if we terraform Mars - not for Martians -but for our own descendants on Mars. If we terraform Mars - but in a temporary way so that it "unterraforms" again in a few thousand years or even in a few million years - what happens to our long time in the future descendants on Mars if they lost our present technology and can't sort out the issues and problems we caused for them. I think we have responsibility for them also, only separated from us in time, that if you set up a planet with an ecosystem that can only last say a few thousand years, if that's how it works out, then we have a responsibility for the inhabitants of that ecosystem a few thousand years form now when it disintegrates. Because we set up the situation that would cause those future beings those problems.
    If your going to use the example at least get it right CHALLENGER not COLUMBIA exploded shortly after takeoff. Columbia disintegrated on re-entry. The astronauts on those crafts deserve more respect than the inaccurate argument presented here.

    Oh so sorry, you are quite right of course. Don't know how that happened. I'll fix it right away.
    Also just to say, like you I grew up with ideas of colonizing space and read all the science fiction stories, Asimov, Arthur C. Clarke etc. Also of course you get dystopian stories about colonization too.
    But generally - without thinking about it much, until maybe about 15 years ago, I just thought in terms of humans colonizing Mars, and didn't give it much thought. But then had gradually wakening realization about how much that could make exploration and study of Mars difficult, even nearly impossible if Earth microbes were introduced by the colonists. 

    So I wanted answers to that question - is colonization compatible with the aims of scientific study and exploration of the planets - and if so how? I tried to find out what I could about that - and not many people talk about it at all - but if you search you do find this whole body of academic literature discussing the very issue.

    And - the upshot seems to be - that it isn't really. At the very least, that it is better not to send humans to the surface - and quite possibly sending humans there would be a scientific disaster, especially in case of a hard landing.

    Once I realized that - then since I have great interest in science and that seems the very most important reason for going into space in the first place - I no longer had the desire to see humans colonize Mars or other places in the solar system, and then started to research more into it and then wrote these articles.

    At any rate that we should go slowly. That right now I feel we shouldn't colonize Mars surface. And as to what we should do in the future, we can talk and discuss it right now, but realistically, everything is going to change anyway, so can't really make decisions yet about what humans will do in the future once we know more about Mars, and indeed about ourselves.

    Every new risky idea needs skeptics, so congratulations for going down in the history books on the wrong side of history.

    Well history will tell after future unfolds. I'm interested to hear what the answers are, if there is a way to make it safe, affordable, and not a major scientific disaster for studies of life on Mars.
    I can think of things that could make it possible for humans to walk on Mars without contaminating it, such as self healing spacesuits, that contain all microbes, and spacecraft that automatically heal themselves even after a hard landing, guaranteed to contain anything within them, and airlocks designed so that no air escapes, and 100% self contained recycling closed system habitats - could imagine that might be possible with nanotechnology, may even be easy in some future technology we can hardly imagine yet, but is way beyond what we can do now.
    Michael Martinez
    I'm not ready to put the future of life in the Solar System in the hands of Elon Musk.  I'm sure he has his positive qualities, as do we all, but I think he is rushing things a bit.
    Now, now, he is the guy who bought Paypal and then named himself a co-founder. Surely he can solve the space problem.
    Solving the space problem is going to to take lots of  people and lots of money, his will do.
    Never is a long time.
    Michael Martinez
    Yes, Elon Musk's money is welcome to the collective effort but I wish he would think more about building space habitats and less about being the first person to stand on Mars.  At some point quality of life is important even for a colonist braving a new frontier.
    I think it would be more practical in both the short-term and mid-term if we figure out how to build self-sustaining space habitats because that would inevitably lead to innovations in space travel which in turn would make an Earth-Mars round trip economically feasible.

    Once you get two-way travel working right you'll see a larger inflow of resources.  By that time, we may have determined that it's practical and worthwhile to terraform Mars and we'll have better technologies for doing so.
    I think we need the equivalent of a tugboat, which would need somewhere in low G to build them. Unless we can loft big pieces and assemble them near the space station. Then we can go places under power.
    Never is a long time.
    We could do a Full mission to Mars this decade. With three launches of a Falcon Heavy for each Mars ship we could start doing "Mars Direct" type missions in a few years. There are a few payloads that need to be finished. The four new major systems that must be developed for that are the habitat systems and its landing system, a pressurized manned rover, and of course the power system must be finished.

    We know the surface of Mars much better than we did our Moon, and we know the gravity is not so lumpy as our Moon. The parachute will be used until near the surface so we will have more time as we get closer and that will give some extra time to find a safe landing spot as it gets close to the surface.

    The Mars Homestead Project is nearly ready and that outlines equipment to bring to build a growing system that can supply all human needs and double that every two year alignments as long as most of the immigrants are productive workers.

    Okay, well I think you are optimistic there, it's all untested technology, just ideas that have never flown. And I don't see the point in it, as explained, it's simply not a worthwhile place for humans to live, like living in a desert, or polar regions or mountain tops or below the sea but far worse. 

    But of course you are enthusiastic about it and think it is a worthwhile place to colonize, so respect your point of view there, though I don't agree myself, as the future unfolds we'll find out what happens. 

    So, if enthusiasts want to fly to Mars or whatever, well what's to stop them except

    1. first the safety - the idea of prospective colonists dying slow and horrible deaths on Mars or on the way there - if you think that's inevitable, then naturally one wants to prevent that and also I believe, it would set back human space flight for decades if that happened.

    But most of all - the whole thing about - would you contaminate Mars with such a mission? Anyway will look at the dangers first.

    1. Closed system habitats - or almost closed, I know you plan to make oxygen by mining ice on Mars - but how easy is that going to be in practise, it's a pretty much unproven technology. Will it work out in practise?

    Then - we have never had a closed system habitat in space. Look at how difficult it is to keep the ISS systems going, and that's not a closed system, they had many issues in the early days. If we could do the ISS as a closed system then it would be a massive financial saving for them, so if it's so easy, why don't the ISS do it? And how practical is it to mine ice for oxygen, really?

    There - it's mainly a case of too much too soon, I feel before going  interplanetary we definitely have to try things like this for long time periods, years on end, closer to hand, e.g. on the Moon.

    2. Landing safely on Mars - I'm not convinced for the reasons given, if it's like the Curiosity landing - then the surface approaches pretty quickly. If it is possible, well you are talking about an immensely complex landing system with lots to go wrong, just like the space shuttle. I think you will get crashes eventually.

    Yes, it's all very well having good images of the surface from orbit, but the atmosphere also makes targetting a spot on the surface harder because it deflects your spacecraft in unexpected ways which you would need to correct instantly while descending, but you don't know how much you are off target - this may be fixed in the future, e.g. ideas for some kind of GPS system for Mars, but we don't have that yet.

    Again - could be a lot safer with GPS for Mars in the future - even so - I think unlikely to be safer than the space shuttle, and would have accidents.

    3. The gravity - nobody knows if Mars gravity is safe for humans long term. Optimists say it will be, but with no scientific evidence to back up their ideas.

    4. The biggy is - how are you going to keep Mars free of contamination by Earth microbes? 

    If not, then what is your answer to the scientists who want to study Mars in its pristine state? What are you going to do about the Outer Space Treaty - and your responsibilities, and the responsibilities of your government, to keep Mars free of Earth life to protect the scientific interests of the other parties to the treaty.

    Even if you don't care so much about that yourself, you have those responsibilities, legally and morally, as citizens of our planet. That you can't make that decision to contaminate Mars by yourself, without the backing of your government and not just that, also other countries, and people world wide who might care about it.

    Do you have an answer to that? I've checked, nobody seems to have an answer. They say that they will fulfill their obligations to prevent contamination of Mars under the OST, Mars One said that for instance, but how they are going to prevent contamination of Mars, especially in the event of a hard landing - nobody has ever explained.

    Even NASA seem to skate over this, they still talk about sending humans to the surface of Mars, but don't have any details of how that could be done without contaminating Mars or greatly increasing the risk of contaminating it. 

    There is the idea of an "exploration phase" - that after that's over it's okay to contaminate Mars. But that's an old idea from the 1970s and the length of the exploration phase has been extended - and even so - is not clear that there would be a final end to it. If it turns out that Mars is of immense interest for biology as many expect, then some at least think that the exploration phase should continue indefinitely.

    And also - the question, if you do want to terraform Mars, it might matter what order you introduce life to it,and introducing aerobes and detritovores at an early stage might cause huge problems later on. Again nobody seems to have an answer to that, they just seem to assume that you'd be able to e.g. introduce green algae, cover the planet with ponds covered in algae, and that no other life forms would interfere with the thing you are trying to do, but of course they would.

    This did not make my previous response available.

    It goes into producing to fill all human needs on Mars and double that every two years if most immigrants are productive. Ways to get the equipment and people there at a modest price, and much more. See the Mars Homestead Project and much more.

    As to contamination. Every year Earth receives about a half tons of debris from Mars, and Mars receives a few hundred pound from Earth. Both have been continually contaminated by the other for billions of years. Any microbes we take to the surface of Mars will be sterilized by UV and the peroxides. Then Mars is so large that if we did it can only contaminate a tiny spot that will take centuries to spread over an area as large as all the continents of Earth. Then Earth life will not be able to compete with microbes adapted to Mars on Mars, and the same with Mars microbes on Earth.

    Most of what you say about Mars is true about our Moon, but not Mars. Again Mars has all we need to be productive. I could be more productive now on Mars than some of my ancestors when they landed on Plymouth Rock in Massachusetts, but then they were not prepared. Within five years I could be ready, and it could be pleasant and productive. Mars has all we need to be productive. Yes it all needs to be processed much more than when we first came to America. Yes they could just cut down some trees and build a log cabin, but they were not even prepared and did not even know how to even do that. We have so much more capacity to process that it would be fare easier for us on Mars than if the Pilgrims were prepared with what was available.

    Okay, on the contamination - that's the sticking point as far as I'm concerned, and for exobiologists also


    1. It's true that there are tons of debris exchanged between the planets. But these all come from relatively few impacts. The debris on Earth comes from impacts on Mars once or twice every million years and the last one was several hundred thousand years ago. This means all the debris we are receiving now, unless a big many meters diameter rock from Mars, has been thoroughly sterilized and has no life on it. Also the habitats for life on Mars are thin fragile habitats, that would probably just be dispersed and destroyed, not lifted into orbit - such as damp sand, thin layers of rock below ice. Any deep down life on Mars is kilometers below the surface, too deep to get to Earth except on the very largest impacts in the early solar system.

    Then the other way, impacts on Earth to send material to Mars are even rarer, every few tens or hundreds of millions of years. The impact that ended the dinosaur era was big enough. But landed in a tropical shallow sulfur rich ocean, not the most likely place for microbes able to survive on Mars.

    And any microbes that do get exchanged have to be able to survive at least a century or so in space, about the fastest trip to get there for meteorite debris apart from a few lucky fragments get there sooner. And survive impact on Mars. And be able to colonize whatever habitat they land in on Mars - the actual habitable habitats are probably rare.

    There might be microbes that made the transition in modern times - though it's far more likely in the early days of the solar system when impacts were larger and when Mars had liquid water on its surface. 

    So - there may well be shared life. But most recent sharing of life was probably during the dinosaurs era - or at least, some tens of millions of years ago. And of all the species of microbes on the Earth - few could survive that journey. 

    This means, that Mars is far more isolated from Earth for microbes than say, Australia, or the Galapagos islands are isolated from Europe or America for higher life forms. Especially given the shorter generation time for microbes also, then if there are microbes descended from Earth on Mars they've had tens of millions, and most likely billions of years of independent evolution.

    And the bottom line is, that it's just a hypothesis that the planets have shared life. It's never been proved with actual direct evidence of a lifeform from Earth on Mars or from Mars on Earth.

    As for numbers of species just humans alone have about 10,000 species of microbes, 1000 of those on the skin, the individual species varying from person to person also - and most of them unknown to science. And about a trillion individual microbes on the skin, 100 trillion if you include those inside the body. The food and air will also have thousands of species. Most of those would be species with zero chance of getting to Mars on a meteorite - but some would be extremophiles able to survive on Mars. Extremophiles have been found on and in the human body - just because it can survive on a human body doesn't mean it loses its ability to survive in extreme environments, extremophiles generally retain those capabilities, and you get polyextremoophiles able to survive in easy conditions and also in many different extreme conditions. Those are the ones most hazardous for contaminating Mars, they are often also UV and radiation resistant to extraordinarily high degrees.


    2. Yes Mars is large but the contamination can spread surprisingly quickly. Remember you have the global dust storms, and that many microbes can enter a very resistant dormant state where they can survive for hundreds of thousands of years, in some cases millions of years in extreme conditions that would quickly kill the living microbe.

    They don't need to reproduce that quickly. Carl Sagan once worked out that a microbe able to reproduce on average once a month, if it landed on Mars and reproduced there, could - if not limited by conditions there as of course it would be - could within a decade, produce as many microbes as we have in the Earth soil over the entire surface of Mars.

    Of course conditions are not suitable for that to happen. But it shows that the life spreading is limited by available conditions. If there are habitats over much of the surface of Mars, as is possible according to two of the ideas (the deliquescing salts, and the life getting water from night time humidity) then life might spread over entire surface within a decade. 

    And whether it spread quickly or not, the dust storms could spread individual microbes anywhere on the surface. Even if you went back a year or two later, you couldn't be sure, if you detected life on Mars, that it didn't come from the human landing even long distances away from the landing site.

    And - it's irreversible, once it spreads. Once you have reproducing life on Mars, spreading in the dust, with these extremely resistant spores - even if the human party gives up after two years and returns, or they all die - this is a contamination that can never be removed again. If there are lifeforms that you would prefer not to have on Mars, either for reasons of science, they are obscuring the science or out competing Martian life - or problematical for terraforming - e.g. aerobes or detritovores that return captured organic carbon back to the atmosphere for instance and consume oxygen - there's no way to remove them once you have spores with lifetimes of hundreds of thousands of years spread over Mars, hidden below rocks, in caves, and so forth.


    3. This is not true either - not proved - after all we know nothing about what life there might be on Mars. Think about rabbits in Australia. The marsupials had millions of years of independent evolution. But the rabbits, just because they explored a slightly different evolutionary pathway, evolved the placenta which no animal in Australia ever did, out compete them and are a major nuisance in Australia.

    In case of microbes, there are two fairly recent ideas that make it particularly problematical.

    First if related to Earth life, to the archaea particularly - these can share DNA fragments with each other - to species even in different phyla, almost totally unrelated species, through the process called Gene Transfer Agents. So if there are archaea on Mars, even distantly related from a billion years ago, then any Earth archaea introduced could share their DNA with Martian life. Resulting in hybrids so you have no idea what in the DNA came from Earth and what came from Mars, especially since the Earth archaea are very poorly understood, almost none of them have been DNA sequences and entire phyla still have no known identified and studied species - the problem of microbial dark matter. And these hybrids might well be h3er and out compete Martian native life - maybe an Earth microbe with bits of Martian DNA, or a Martian microbe with bits of Earth DNA.

    Then you also have the possibility, the most interesting one, that Martian life uses XNA, different basis from Earth life. Then - that would be a totally unexplored possibility and you basically have three possibilities - that XNA and DNA can coexist, that XNA out competes DNA everywhere or almost everywhere, or that DNA out competes XNA everywhere. All of those are problematical. 

    If DNA out competes XNA then Martian life would go extinct. If XNA outcompetes DNA then Earth life goes extinct. If they can co-exist, then you get DNA taking over from some of the Martian life - and XNA taking over from some of the Earth life - and those also are major changes like introducing rabbits to Australia. Might change how an important part of an ecosystem works on Earth for returned XNA.

    Now - not saying any of that would happen. But we only know if we study what is there on Mars before we do anything. I'm saying we shouldn't just go there blindly. And that we do need to explore and study Mars first - and then the immense science value of what we can discover on Mars, and the problems with terraforming etc. We need to know, not just introduce life and hope for the best.

    That would be like the early Europeans who introduced rabbits to Australia for sport and a reminder of home, not realizing they were causing major future problems for the Australians.


    With your ideas for the surface of Mars - well apart from the atmosphere, which I think is a rather overrated resource as CO2 is not hard to create, most often in space habitats you are trying to get rid of it - and to get it from the Mars atmosphere you have to pump it in out of a laboratory vacuum - well the rest is available in space. If keen to explore Mars, then you can mine Deimos or Phobos, and explore the Mars surface through telepresence - and the Martian Moons directly.

    Those also have planetary protection issues, not so great as Mars, so would need to be studied first, but could be studied adequately to know if it is okay for science to colonize far more quickly than Mars itself.

    Or you could use materials from the Near Earth Asteroids. If looking for somewhere nice to live, and also if the motivation is to export materials to Earth to fund your colony, a free space colony in orbit around the Earth or the Moon would be more viable, pretty sure. 

    It doesn't make that much sense to look at the surface of Mars for that. Indeed for valuable materials to export to Earth - you get valuable metals in the asteroids for instance, and other resources that would be hard to mine on Mars.

    Also in space you can have cosmic radiation shielding, but have it around a large spacious habitat, even kilometers scale, spinning Stanford torus for instance. You can't do that on a planetary surface.


    I know that Robert Zubrin makes all the arguments you make, and he's a brilliant engineer and has many good ideas, and involved in many innovations for space exploration.

    That's all accepted by everyone of course - and often it can seem as if his arguments about contamination and colonization are also accepted by everyone and uncontested. But in fact, he is a vocal minority in the academic literature in that field. 

    I don't think many scientists, outside of the Mars colonist enthusiasts, are convinced by his arguments here, especially about contamination of Mars. For the reasons I just gave. They don't stand up to close scrutiny.

    I go into this in more detail in my other articles here such as

    Why Mars is NOT a Great Place to Live - Amazing to Explore From Orbit - with RC Rovers, and Nature Inspired Avatars

    where you'll find a section towards the end answering Zubrin's Mars contamination arguments case by case.


    Could Microbes Transferred On Spacecraft Harm Mars Or Earth - Zubrin's Argument Revisited

    LOL, you have no idea what you're talking about. Plymouth rock, indeed!!

    You're overlooking the little fact that the pilgrims survived because there were people already living here. The only people that considered it "wild" or a "frontier" were the idiots from Europe.

    The rest is just optimistic drivel that has no basis in scientific fact. The reality is that, given present technology, you won't live long enough on Mars to be "productive".

    This is some of the most infantile blather I have had the misfortune of seeing. Most of the problems described here amount to "it's scary", or "it's difficult"; who the fuck cares? People died colonizing the Americas-- in droves.

    Death isn't the worst thing which can happen to a man; being a coward is. I'm looking at you.

    Michael Martinez
    "Death isn't the worst thing which can happen to a man; being a coward is. I'm looking at you."

    Signed: Blaeaka

    Self-immolation through irony is one of the Internet community's most common fallacies.

    No, I think being stupid is worse. Congratulations!!


    Sure, if that was all, well you could say, is up to the Mars colonists to risk their lives if they want to, as with people involved in dangerous sports, like base jumping, it's probably more dangerous than base jumping is my guess. and I wouldn't do that, but if people do - well it's their decision. Who else's business is it, if they want to take that risk?

    The difference though, from such risky activiites as e.g. base jumping etc - is that by contaminating Mars, you can lose something precious of immense value for humanity.

    Like - suppose that they could get to Mars but only by destroying all the paintings in the Louvre or the Museum of Modern Art? Well rightly art lovers would protest. While those who don't care about art at all might not be bothered.

    For exobiologists, what you'd destroy on Mars is just as precious as that, and more so. And as well as that it's something that could be of immense value to society also, if you think about how much we depend on the processes of life, and what a difference it could make to have an improved understanding of life on a fundamental level.

    For more about this, How Valuable is Pristine Mars for Humanity?

    That's something that we might later need to travel for light years to another star system to find, and quite possibly won't find anywhere nearby in our galaxy. At least - that's the situation if it's right that Mars holds the keys to understanding the early stages of evolution - also potentially, could host life that evolved in different directions, maybe even not based on DNA.

    And if you want somewhere to build homes, there are masses of resources in the asteroid belt, and technology to convert that into space habitats is arguably probably easier to develop than technology for an alien planet surface with low gravity, and near vacuum atmosphere - you can spin up for gravity, can have spacious interiors for living in. A Stanford Torus or O'Neil cylinder is far more spacious than any design for a surface colony I've seen, and you can go anywhere you like inside without protection, without spacesuits - and build ordinary type bulidings inside the habitats also. 

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

    I think myself will be a little while before it makes sense economically to go into space to colonize. But if we do, then using materials from the asteroids is as likely to succeed as anything - and has huge potential, more than a thousand times the surface area of the Earth just with materials from the asteroid belt, far more living area than you could create on planetary surfaces. 

    If you are really keen to explore Mars, if you do it via telepesence, then there's enough material in the Martian moons to create radiation shielding for more than the size of Scotland, about same as area of Colerado or Oregon - can create that much living area, fully shielded from cosmic radiation, Earth normal atmosphere with no need for terraforming a planet, lakes, rivers, no dust storms or hazards from the perchlorates in the dust, tropical temperatures (if you want) - the problem with space habitats is generally to keep them cool with radiator fins.

    You can do that using just the materials from Deimos (assuming it's okay for planetary protection to mine Deimos). It's also going to be easy to send materials to Mars orbit from Earth using the interplanetary super highway.

    And you can mine Mars too eventually - via telepresence, if there are valuable resources there. Use fuel made on the surface, automated rockets to take it to orbit, and no need to land human habitats on the surface. Just as with oil wells, and deep ocean drilling, there's no need to have anyone down there in person to do the work, especially as automation gets better and better. You can grow trees also on Mars, and higher plants, in hydroponics, as their seeds can be sterilized. It's the microbes, not the higher plants that are the problem. 

    It would be fine to have humans on Mars if only there was some way to get there without also taking all the microbes that hitchhike on every single human being. But so far no way known to do that, if you sterilized a human the way you can a plant seed, we'd die.

    There's no urgency to have humans on the surface of Mars.

    That HERRO mission sounds quite exciting.

    When I was a boy, in our local library there was a book by one of the great space illustrators, showing the planets of the Solar System as viewed from their various moons, for example Saturn as seen from Mimas and from Phoebe, and many in between.

    To get that for Mars, all in one orbit ...!

    As for home in an asteroid, in some ways that beats the Little House on the Prairie hands down!  But what favourite houseplants would I take with me?
    Robert H. Olley / Quondam Physics Department / University of Reading / England
    You are right to be concerned about the martian life if it exists and even about keeping pristine matian conditions in the name of science. I am OK with that . But I think there is an other very important reservation about landing on Mars without much precautions.
    what if this life on Mars is deadly to our own terrestrial life ? Impossible ? Well remember what happen to the indians when they caught the europeans microbes.
    If there is life on Mars the planet must be quarantined and this life and its interraction with ours must be studied in situ or in martian orbit in very secure labs.
    And only when we are sure there is no danger that a landing can be authorised.
    Doing otherwise would be playing russian roulette IMO.


    Yes, that's also true. That's also the main reason I think plans to return materials from Mars to Earth unsterilized are ill advised myself. Not when we have no idea what is in them, when there might be e.g. Martian life based on XNA, with completely unknown properties and capabilities and sizes, or archaea able to transfer DNA to Earth life via nanometer scale Gene Transfer Agents just a few tens of nanometers across. They plan to contain the samples - but how can you guarantee containment, and yet be able to open the container and analyze what's in it, when the things to contain are potentially so small even the most powerful optical microscopes can't see them, only electron microscopes?

    The very best way to study it in any case is "in situ" first with landers and rovers from Earth and then via telepresence from orbit. We have many excellent biological instruments, miniaturized, that we can send to Mars, ExoMars will be first to attempt this since Viking (Curiosity can't detect life unless it is very obvious and in large quantities).

    That's the safe way to do it, nothing gets returned to Earth. Then as you say, to return samples to orbital laboratories, robot handling, in orbit around Mars ideally, no human goes anywhere near them. Could also return to the L2 position, far side of the Moon similarly if that can be done with total safety not to contaminate Earth.

    In any case returning a sample from Mars is prone to failure if we do it right now. I know it is NASA's long term objective for 20 years from now. But it's not so widely known that one of the white papers submitted to that same decadal review was by a group of exobiologists who advised strongly that it is not a good idea to focus on a Mars sample return for biology. Why they don't listen to the biologists on this point, when the main aim of the sample return would be biological, is beyond me!

    First chirality signatures, even biosigantures don't have to mean life, as you get them in material from meteorites also. So until you have an unambiguous detection of life, you don't know what is in the sample and it is as likely to be no more interesting for biology than the Martian meteorites we already have. It may also be hard to cultivate - if you return a sample then it might no longer have living organisms in it.

    Some day surely we will want to return samples. If it's completely unknown what's in it still, I think the only really safe way is to sterilize it, which you can do quite easily with gamma radiation, send a portable gamma sterilization unit on the space craft. That has similar effect to, say, a few hundred million years of surface radiation on Mars.

    Because, after all, until we know what it is, in worst - or most interesting case - it could be XNA and then all bets are off as to what effect it could have on Earth life and ecology and vice versa, for same reason that biologists studying the possibility of creating XNA based artificial life in a laboratory consider it something that is potentially extremely hazardous only to be done with numerous precuations to make sure it can't possibly reproduce outside the laboratory, even if it does escape. But we can't guarantee that for Mars life, because it's not artificial engineered life, it may well be able to reproduce and spread over the Earth and outcompete native lifeforms, transform ecosystems. The worst outcome (highly unlikely surely but still, has to be considered, because it is such a major issue if it does happen) is "Goodbye DNA, Hello New XNA World".

    I suggested that for any scientists who are really keen to return a sample, as in the NASA plans, that just possibly might have Martian life in it, and which is interesting in its own right - that a better place than Mars to go is to the moon Phobos. The surface of Phobos has a surprising amount of material from Mars in it according to recent estimates - which just possibly could contain evidence of life. And - it would be no harm to sterilize it to be sure there is no viable life in it, because most of it has already received millions of years of cosmic radiation. Though not currently a planetary protection requirement for sample return from Phobos, I think myself that it should be done just to be sure.

    It's also far more viable financially than a return from Mars surface. But I do think a Phobos sample return also should be sterilized at this stage of knowledge when we still get so many surprises every time we explore new places in the solar system. Why Phobos Might be the Best Place to go for a Sample Return from Mars Right Now

    Apparently Elon Musk has a number of credible accomplishments to his name, like high-end electric vehicles (Tesla Motors TSLA +1.42%), so surely we could give him the benefit of the doubt, there's is a possibility he might know what he is doing, the 2020's might be a bit hopeful though, we do have accelerated advancements in technology I don't believe it's possible for such extensive research and development to be done so soon.

    I agree with Micheal Martinez, humans do have an embedded desire to grow, and Elon Musk has the perfect personality to see through his idea, it might cost him a lot more than he budgets for and could fail miserably as this blog so meticulously puts it but "The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man."

    Space exploration and inhabitance has a whimsical feel to it and I believe that is what most explorers hold on to.


    Oh I think it's possible he might be able to make a rocket that can land with some level of safety on Mars. Given the complexity of this, even with his novel ideas, I'd be surprised if it can be safer than the space shuttle, and wonder how you could prove that. But- one that you are totally sure can't crash on Mars - and also with ability to contain microbes on arrival to the same standards and higher than a biohazard facility on Earth - and spacesuits able to do that also?  I think that's beyond what he could do. So then those contamination issues arise. 

    Especially - how does he plan to protect Mars from Earth life in event of a crash on Mars? No point really in talking about his plans for planetary protection for spaceships and spacesuits, whatever they might be, if you can't do it in event of a crash. I expect he has given it little thought so far, at least he doesn't talk about it as far as I know - but would have to if it ever came close to reality. Yes he can make things happen, and what he's doing with Space-X is amazing!. But also a person of big ideas that don't necessarily all come to anything.

    The other issues of whether you need artificial gravity and if so how, close habitats etc - maybe some day can be solved. So far I don't think Space-X are even working on those particularly, just on ways to get large amounts of mass to Mars, and certainly nobody has got a closed system habitat in space, never have, only habitats like the ISS that need continual resupply from Earth every few months and disposal of waste burning up in atmosphere - just experiments mainly in Russia on the ground and things like Biosphere II.

    Elon Musk is a very enterprising guy. He has succeeded at a lot of stuff others would have given up trying long before he did. Like Edison who is said to have made 10,000 experiments until his vision of the incandescent light bulb worked. That said though, recently Musk has started a mix of enterprises that makes one wonder if he's like the guy who believes he can walk on water because he saw someone else do – only that other guy knew where the stones lay, close to the surface. His space ships work as he has shown. And Virgin's Branson can do the same thing – because it's physically possible. But I tend to think Musk's Tesla venture will eventually be a failure like all the other electric cars that went before them – Siemens had a world-renowned electric car at the turn of the century before last (the "Proton") and won prices with it. Musk has deep pockets but he doesn't understand that any Mars mission will bankrupt him. He may think the state will help finance it. But not so, the US is already broke. George Bush junior thought he could pull a Kennedy II by announcing with Mars what Kennedy promised with the moon. But he never said where the money was. He left that to his successors. Musk doesn't seem to understand politics enough to understand his Mars project is doomed for the very reason that it does not provide any profits, even in a very long run. The times where the state would finance such hobbies are long gone; they can't even make terrestrial solar panels profitable, let alone fusion. Mission Mars will be in another century.

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