In Edgar Allan Poe’s story The Masque of the Red Death, a horrible and deadly plague sweeps the world, and the wealthy Prince Prospero attempts to escape it with a group of hand-picked loyalists, walling them up in a fortified, isolated and richly-provisioned facility, complete with an orchestra and a masquerade ball. They intend to hide in safety and comfort from the Red Death while it ravages the broader world, but (and here’s a spoiler for this 19th-century story) the plague nonetheless finds them and they die anyway. In their arrogance they cannot wall themselves off from disease, nor from the suffering of humanity, no matter how much wealth they have, no matter how removed is their castle from the populations they leave behind to die.
Mars, long a staple of sci-fi visions for human expansion, is in fashion again as a target for colonization. In particular, it’s sometimes advanced as a lifeboat to escape threats to life on Earth – wars, environmental disasters, killer asteroids, or lately, plagues. And in particular, such visions are currently being popularized by latter-day Prince Prosperos – wealthy and eccentric figures with loyal followers eager to dance at the ball.
Setting up a Mars colony to escape problems on Earth is arranging a Masque of the Red Planet. And like the party in Poe’s story, it is both monstrously unethical, and deeply ill-advised. And like that party, it will end badly.
It’s quite plausible that humans might visit Mars, and that astronauts might make an important contribution to science and exploration on that planet. It would be a tremendously expensive program, and it would require a number of significant technical advancements – life support systems including extensive recycling, sustained deep-space operations, crew support with long delay times, landing very heavy things on Mars and launching them again, in-situ production of consumables, and more. But I do believe it’s possible. That’s not what I’m talking about at present, though. I’m talking about settlement, including the idea of settlement as a back-up plan to survive a catastrophe on Earth.
Now, we might feel like we have all our eggs in one basket by living on a single planet, but risk is not reduced by putting some eggs in a flimsy basket with holes in it. So what makes for a barely adequate second basket? To act as a backup to Earth, a Mars settlement needs to be able to sustain itself long-term without relying on Earth – it needs to be an independent basket. A sustainable Mars settlement thus needs to have most of the technical capacity of a civilization on Earth. It must have:
This, like Prospero's masquerade ball, is not a simple party to plan. Some of these requirements present massive technical challenges. I won’t go over all of the technocratic matters here, but in short you’re asking for things that have never been done, in a place where it’s not clear the raw materials even exist to supply inputs to what you need to do. This is a very tall order, and there are huge risks, to use the engineering meaning of that term. But if you were so inclined, you could wave that all away with techno-optimism… or simply with ignorance. You could suppose that we just need a few brilliant inventors, that the march of human progress will inevitably solve technical challenges, or even that the advent of wondrous artificial intelligence will allow us to transcend all manner of technical problems we couldn’t before.
There are two pressing concerns, however, that for the moment obviate the need to resolve these technical problems. The first is about human physiology.
Mars is a terrible place to live. Everywhere on Earth is better. Even in the middle of Antarctica you can at least breathe, and with little effort melt the snow to get water. Mars presents numerous threats to human heath, including (but not limited to):
We can come up with solutions to the first three points, though the perchlorates are a real hassle. But this fourth one, the surface gravity, is not going away. You can make ‘artificial gravity’ in a large enough weightless spacecraft by rotating it, but on the surface of a planet this is impractical. The only thing you could do is make Mars itself a lot more massive, which just isn’t feasible. Even if humans living on the planet spent all of their time in some kind of pressure garments or compression harnesses holding them down to the floor, their internal organs still wouldn’t feel the effects and would effectively be at 0.38g.
Maybe 0.38g is fine. We don’t know. But it would have to be fine for the entire life cycle of the human being – conception, gestation, childhood, puberty, adulthood. Everything that happens — growth, cell division, gene expression, hormone-mediated development, and much more — through all of that has to work more or less correctly under 0.38g for life in a Mars settlement to last even one generation. And we have no reason to believe that’s the case. Basically all of the data we have on low-gravity effects on humans and other organisms is from weightlessness, and (especially for humans) the news is pretty much uniformly bad. Ask yourself what experiment we would even have to do to convince ourselves that children could be conceived, born, and grow to maturity in low gravity. Think about the ethics of such an experiment.
One way to start down that road would be to extend our experience with weightless Earth-orbiting space stations to a fractional-g environment. The Earth’s moon offers a convenient place to try this out; the acceleration due to gravity on the lunar surface is about 0.17g, so a lunar surface station, staffed as the ISS is with astronauts on rotations of months at a time, would give us data to compare to the weightless experience. The lunar environment is similar to Mars in several other respects as well – high surface radiation, vacuum requiring pressurized habitats, dust and soil which are somewhat hazardous (for different reasons), so it’s a pretty good place to practice for Mars. It also has the advantage of being nearby, which is both convenient, and will be very helpful if things go badly and we need to evacuate our people. Years of lunar-surface operations could help us understand how humans and other organisms handle low-but-not-no gravity, and act as an important step towards knowing whether it’s even possible for us to live in Mars gravity at all.
We should accept, though, that the outcome of that work might be that no, it isn’t possible for humans to live and reproduce on Mars. If that's the case, then Mars is a basket with holes bigger than our eggs, and putting people there doesn’t reduce the risks to humanity’s survival.
Even if we can solve the technical problems, and even if many years of experiment and experience in the low-gravity lunar environment teaches us that partial-gravity is probably fine, there are even bigger problems with Mars as a backup planet. The need for such a backup planet – a lifeboat for Earth, a second basket for our eggs – arises from the premise that there are existential threats to life on Earth. Mars is useful either because that planet would escape some of those threats, or for simple statistics: two shots at escaping disaster are better than one. Do these ways of thinking about the risks make sense for the threats Earth faces? Well, what are the threats? What are the risks faced by humanity which are existential in nature – which threaten the extinction or near-extinction of human life on the planet? Here’s a list:
Number 7 is a real concern we’ve been forced to pay attention to again recently. If people are moving between Earth and some future Mars settlement, they’ll carry that disease with them. And if diseases can arise in the Earth population, they can arise among the Mars settlers too. As with Prospero’s masquerade ball, you can’t wall yourself off from disease forever.
Numbers 5 and 6 are the stuff of science fiction. If either does appear, there’s little reason to assume they would spare a human settlement on Mars when wiping out the Earth’s population from either malice or neglect.
Number 1 is interesting because it’s a real threat; we know that massive impacts have happened on Earth (and Mars) in the past, and are certain to occur again on very long timescales. We also know that mass extinctions have coincided with at least one of these events. The good news, though, is that we’ve also applied science (specifically, astronomy) to this problem, and we now have mapped the positions of virtually all of the asteroids in the solar system big enough to threaten mass extinction. And we’re well on our way to finding all of the ones big enough to cause regional destruction, so there’s very little chance of even a regionally-devastating event happening without many years’ notice, and those chances get smaller as we continue our telescopic surveys. And there’s more good news – we have some rough-draft technologies for redirecting the orbit of such asteroids, should we need to. Now for the bad news: the ability to redirect an asteroid away from turning a major city into a massive crater is also the ability to direct an asteroid into destroying a city, which means inventing the technology to save ourselves from threat number 1 just transforms it into threat number 3.
So now we’re left with numbers 2 through 4: war, deadly weapons, resource exhaustion and collapse. Whole fields of study exist to understand these problems. Countless books, papers, and graduate theses have been written trying to understand them. And yet, it is not an oversimplification to say that these are all social problems. These are problems of how humanity lives together and shares resources, how we relate to each other as individuals and as communities, and how we come into conflict with each other over our needs and ambitions. Wars are conflicts between communities of humans. Weapons are a problem because of the chance they’ll be used; the threat of such use shaped much of the politics of the twentieth century, and drove the relationships between the nations of the Earth for much of that time. And failure to manage resources is very much a question of how we structure and organize our society; if we allow ourselves to use more resources than can be sustained, we will of course run out.
All of these threats emerge from a failure of humanity to govern itself – to live together and within our means. And they are all open problems. We still have war. People start new wars pretty regularly around here. Why? Again, much has been written on the subject, but whether it’s conflicts over resources, lust for power by leaders, hatred born from cultural or religious differences, or rekindling of historical grievances, it seems like most of our wars emerge from a failure to live with each other within the limits of our resources. The weapons mostly are created to use in those wars, or sometimes with the idea that they are so frightening they might prevent war (this hasn’t been especially successful). And who would use such a weapon outside of war? Someone with a grievance akin to the kind that starts wars? Someone who is either deeply failing to live in community with the rest of humanity, or who is reacting violently to such a failure that has affected them? In any case a society which permits world-ending weapons to exist such that they might be used is a society which hasn’t yet figured out how to avoid the creation within itself of threats to its own survival.
The same can be said of a society which hasn’t yet learned to make sustainable use of the resources which it depends on, and we are, evidently, still such a society. We know we’re causing climate change that will be massively disruptive to our societies’ needs. We know we’re taking fish from the ocean faster than they can be replaced. We know we’ve built our economies on non-renewable resources that will run out remarkably soon. We know we’re causing a new mass extinction with habitat destruction and pollution. We know of many other problems we are causing for ourselves because our societies are not organized to provide for our needs within the limits of the resources available.
Once again, much has been written on why we still do these things. But we haven’t gotten them out of our system yet, which means if we go to Mars, like an endemic virus we will bring these things will us. Until we learn to live together without starting wars and building weapons and exhausting our resources in a way that threatens our own destruction, a second planet won’t save us. Even if you think there is another reason for poverty, war, or ecological catastrophe which I haven’t mentioned here, ask yourself: does that reason go away if we live on Mars instead of Earth?
If humanity on Earth is existentially threatened by war or its tools, or by an inability to manage finite resources, then humanity will be existentially threatened on Mars by this same failing in our social structures. The statistical argument (and it's a statistics of very small numbers) isn't much comfort here either; a second basket is of little use if we keep cracking our own eggs. A lifeboat is no good if our problem is that we lack the discipline not to scuttle our own boats.
Until you can build a society without war, and without unsustainable resource exploitation, settling Mars is of no use in ensuring the future of human society.
This matter of resources requires further attention, though. It’s not just a question of using them up unsustainably – it’s also a question of allocating them. On Earth, many of our resources are plentiful and freely available. In many places the weather is clement and comfortable much of the time. If it’s not too polluted, you can simply go to the nearest river to get water to drink. Food takes more work, but air is completely free. You can breathe as much as you need anywhere you go. (Granted pollution is an issue with the air, too.)
What this means is that if society fails to allocate resources to provide for everyone, it’s still more or less possible for those whom society lets down to survive on the margins. Even if you don’t have a house, and can’t afford to pay rent, you can, as a last resort, go sleep in the park (or if the police chase you from there, in the woods at the edge of town). And you can breathe the air and perhaps find water. And you can live, hungry and miserable, for a long time on a sparse, irregular, and nutritionally inadequate supply of food which you could spend much of your time trying to obtain. Sadly, many of us do have to live this way because, like war, our societies have not yet learned to expunge themselves of the causes of poverty – even in the wealthiest communities humanity has ever known. But it is possible to live like this, even if you live in misery, and for a shorter time.
It is not possible to live like this on Mars. You cannot sleep outdoors on Mars. You cannot breathe air for free, and you cannot take water from the river. If a society on Mars cannot figure out how to provide shelter and basic resources for all of its inhabitants, that society will very quickly have an absolute crisis on its hands. In the closed habitat of a Mars settlement, where all the air is manufactured, all the water produced by one technologically-mediated process or another, and all the space carefully-apportioned, resources are extremely scarce. If the society occupying that habitat has not learned to organize itself such that the basic needs of all of its people are met by its extremely limited resources, all manner of horrors lurk. What choices will need to be made if resource production is below expectations or below needs? If consumption is higher than expected? If population grows faster than planned? The only way to avoid the kinds of horrors such decisions would bring is with the wisdom to organize society robustly and justly, and the planning and forethought to provide what is needed to do so.
This means that you cannot build a city on Mars until you can build a city without homelessness. This is true in the sense that we need the wisdom to organize a society that well, but also literally true in that you cannot be homeless on Mars, where you can’t just leave mainstream society and live at its margins on the unmanaged resources.
I started by pointing out that there are many technical problems that need to be solved to send humans to Mars. These problems remain, and many are being studied. The people studying them may one day enable astronauts to visit that planet, but their efforts are insufficient to allow us to live there. Indeed, it may be that human physiology proves to be unadaptable to the Mars environment, and we have much work to try to determine that before we can ever think of settling on that planet. The people who build the programs and technologies needed to study this will also be making necessary, but not sufficient, steps towards understanding whether we can build a future on Mars.
But a Mars settlement is doomed if it suffers from the same problems we have on Earth. Here where resources are plentiful, we have still not learned to live within their limits; on Mars where the management of resources will need to be much more sophisticated and will be much more critical to avoiding prompt disaster, our existing tools are certainly not adequate. This means that the real work of learning how to bring about the Mars-settling future is not being done by engineers and technologists. The work of building that science fiction world where humanity expands out into the solar system and perhaps beyond is the domain of the social sciences. The technological problems are tremendous, but they are small compared to the sociological problems we need to resolve.
Everyone learning how to build governance structures to prevent war. Everyone working to disarm the world of nuclear weapons. Everyone working to lift people and populations out of poverty, to build not just stopgaps but robust systems to prevent homelessness. Everyone working to make our society more just and equal, such that we can reliably ensure that everyone gets the resources they need to survive and thrive. These people are the ones building the tools we need to live on Mars. If it’s possible for humanity to settle there, it is only possible once we resolve these sociological problems. And when we do, we will have at our disposal a human race able to bring all of its efforts to bear on such aspirations, because we won’t waste whole lives struggling to survive; the people who would have been homeless and desperate will be able to spend their attention on the technical challenges we like to think are the main problem. Humanity will be more capable because it will not be suffering through the misery of poverty and war, nor the consequences of them.
Once we do that, it won’t matter if our physiology isn’t suited to Mars; we can thrive here on Earth while exploring Mars as we like for short periods. Or we can build rotating cities in interplanetary space, if we still find off-world settlement inspiring. We can, perhaps, even reach for the stars. But if we want to do these things, we must first build the society that can produce them. And if we want to ensure humanity survives, we must care for the basket our eggs are currently in.
This isn't an essay proclaiming that we must solve problems here on Earth before going to space. This is a declaration that those two challenges are one and the same. Solving the technical challenges is not enough if we don't solve the social problems, and in fact the social problems themselves belie the greatest technical problems. And doing what it takes for humanity, each person and every person, to thrive on Earth is also making humanity more ready to move outward from the Earth.If some Prince Prospero tries to sell you a technocratic vision of a Mars colony as a way to save humanity, he is selling you a Masque of the Red Planet. It is doomed to fail because these other problems have not been solved. And if he uses vast wealth to arrange this masquerade for a privileged few, this effort is worse than pointless – he is hoarding the resources which humanity could use to solve the real problems that stand between us and that beautiful future, and he is wasting resources at a time when humanity has not learned to live within our means. Such resource hoarding in a time of poverty and suffering is a cause of the threats which the doomed Mars colony is the proferred solution to. It is thus misguided and unethical, but it's also doomed to fail as a way to ensure humanity's survival. That means it's a scam, and it’s not the road to the beautiful future it promises.