Living on Mars would probably suck — here's why

<Music>

Benjamin Thompson

Welcome to episode seven of Nature hits the books, the show where I chat with authors about their science books. In this episode, I'm joined by Kelly and Zach Weinersmith, whose book 'A City on Mars: Can We Settle Space, Should We Settle Space, and Have We Really Thought This Through?' was published at the end of last year. As the name suggests, it's a book that takes a deep-dive into the whys and why-nots of setting up shop in space, looking at the psychological, environmental and legal obstacles in the way of achieving that goal. A few of the things we talked about on the podcast.

<music>

Benjamin Thompson

Kelly and Zach, thank you so much for joining me today.

Kelly Weinersmith

Thanks. Yeah, we're thrilled to be here.

Benjamin Thompson

Kelly, you're a parasitologist, right. And Zach, you are a cartoonist and an artist. What was it about plans in the future to settle on Mars that made you go, like "d'you what, this is something that we need to write a book on"?

Kelly Weinersmith

Well, we both are sci-fi nerds, for starters. And this is the second book that we've worked on together. And in the first book that we worked on together, there were two chapters related to space that made us think that even though for generations, people have been saying space settlements are just around the corner, we thought, but we're gonna be right this time. And so we decided we were going to write the near -term guide to space settlements, because that sounded like a lot of fun. And that's not the book we wrote.

Benjamin Thompson

Right? Well, the title of the book, I've got it here in front of me: 'A City on Mars: Can We Settle Space, Should We Settle Space, and Have We Really Thought This Through?' And I think the full title of the book maybe gives a sense to your thought process as you went through? Is that fair to say?

Zach Weinersmith

Yeah, we actually spent a lot of time on that, because we wanted to convey the topic, but also a tone and the tone was like a kind of winking 'oh, my God, I don't know if this is a good idea'.

Benjamin Thompson

I mean, you do describe yourself both as quite hefty space nerds, right. So I guess you are fans going in?

Kelly Weinersmith

Yeah absolutely. It was an uncomfortable journey, actually writing this book. For the first two years, we were writing the book as though like, 'oh, space settlements, they're coming, they're awesome'. And then the next two years, we're like, 'oh, actually, this is much harder than we thought. And we should probably slow down'. And it was our editor, actually, one day, who sat us down and was like, 'you too, clearly are not writing the book you pitched. And that's okay. Just accept it, and like, form a new thesis'. And we're like, ah, yeah. All right.

Benjamin Thompson

How did that feel to be like to be like, 'do you know what, actually maybe not?'

Zach Weinersmith

Extraordinarily anxious. I mean, I think someone else would have felt really cool. Like, they were gonna charge in and argue with people, but we're just like, absolute cowards.

Kelly Weinersmith

Because we've become friends with these people by that point. And like, I want to believe we're still friends with a bunch of the space settlement people.

Zach Weinersmith

Most of them.

Kelly Weinersmith

But a lot of them were not at all happy. And I think a few felt like we hoodwinked them, because the book isn't how we pitched it initially. And, you know, we weren't trying to pull the wool over anyone's eyes, you know, our thoughts changed over the course of the research.

Benjamin Thompson

Well, let's actually talk about the book itself. Let's start with some of the reasons why folk think that we should be colonizing or settling space. And I appreciate that those are both quite loaded phrases. And people have been thinking about the best phrase to use to describe that process. But it's not just Mars, I mean, I know that's the title of your book. It's other parts of the Solar System, as well. But off the bat, what are some of the reasons why people think it's a good idea to do this at all?

Zach Weinersmith

So I mean, there's a lot of them, but one way to divide it would be like, some are arguably pragmatic reasons, like, well, there's so many resources in space, we should go because we'll get rich with like space-based solar, or asteroid mining. And then there's sociological things like what will become more collaborative as nations if we do stuff together in space, or space willl just be so objectively awesome, we'll realize how puny and silly all our fighting is. They're also just human nature arguments, like it's in our nature to explore and so like, the nice thing about space is because we keep not doing it, it kind of maps to any fantasy. If you have a fantasy of leaving capitalism behind, you can do it on the Moon, if you have a fantasy of like, actually, capitalism doesn't exist yet, we need to do it on the Moon. That works fine, too, because we're not there yet.

Benjamin Thompson

Were there any specifically that you going in cold when you started this off were like 'do you know what, this is kind of for me?' Like I've written two good reasons down here. One is the Cathedral of Survival. And the other is the hot-tub argument. I put these down in the good reasons in inverted commas. Were these things that maybe you both subscribe to in some way?

Kelly Weinersmith

Yeah, so the hot-tub argument is essentially that it's awesome. And no-one has a right to tell you, you can't have it. And then the Plan B or the Cathedral of Survival argument is that species that are found in lots of different places have lots of diversity are you know spread over wide regions, there are species that are more likely to persist for long amounts of time. And so folks like Elon Musk are arguing that we need to be interplanetary as like the ultimate safety-system for our species. So if something catastrophic happens on Earth, then at least we've got some humans on Mars, so the human species will persist. But we ended up thinking that the Plan B argument needs to be sort of reformulated a little bit to think a lot more long-term because our ability to create a society on Mars that could survive the death of Earth is probably generations away. So people living on Mars for the foreseeable future are going to require supplies from Earth to continue existing. Otherwise, all you're going to have is a delay between the destruction of Earth and the destruction of the species on Mars.

Benjamin Thompson

Cheery then.

Kelly Weinersmith

Yeah this is why they don't invite us to their parties anymore.

Benjamin Thompson

It does seem to me they're on a track to this actually happening, right? I mean, that technology is becoming more affordable, more advanced. On the show, we've covered a bunch of the Moon landings recently, of course, just at the start of the year, Japan did the most accurate Moon landing to date. Obviously, folks are thinking about this arguments are going on about how feasible this is. And for some, it's more feasible than others. But given that your book seems to have this 'woah, steady on' message, do you think this is something that is needed?

Zach Weinersmith

Yeah, our feeling is that both the public discourse and actually a lot of the beliefs that seem to be held by powerful people are not always tightly moored to the facts. To give an example, you will regularly see articles that say there will be some sort of permanent gas station on the Moon uses the water on the Moon to make rocket propellant. And of course, you can do that. But it just turns out, when you look at the numbers, there's not that much water. And that should obviously be front and center when you're talking about some sort of ability to use the Moon for this. And it turns out, there's just all sorts of examples like that. And unfortunately, a lot of these ideas that just don't pass an envelope, mathematical test get spoken by like agency heads and billionaires. And we'd like that to be improved.

Kelly Weinersmith

And I'd also like to note that we distinguish between exploration, which is like, amazing things are happening right now. And we'd like to see all of that continue, and settlement, which is where you're bringing families and having babies and you're staying there for generations.

Benjamin Thompson

There seems to be a few key themes, I think, in your book, at least to me. So 'people', 'where's the best place to go' And then there's 'ethics and regulations'. And I know some people listen to this podcast be like, 'oh, good ethics and regulations, yay'. But actually, that is a whole topsy-turvy world, off-world, I suppose. First, let's talk about where you might go. And the title of the book is City on Mars. And that's one place, but the Moon seems to be potentially the most achievable in terms of like, we've been there a bunch. And if he wanted to settle somewhere, that'd be the first place to go. But of course, it does have significant pros and cons.

Zach Weinersmith

Yeah, the Moon is probably the place to start, basically, because it's always close, you can almost have a live conversation, it takes about a second for data to get there at lightspeed. And you can always get home in like a day or two. Whereas Mars, you know, there's a point in time when it's on the other side of the Sun, and you just you literally can't get back unless you have like technology from Star Trek. So the Moon is a great place to start. But it has really big problems, as an example of something that's a real showstopper the Moon is very poor in carbon. So you may have read an article that says you can grow plants in lunar soil, but it would be better to have the headline be you can grow plants and lunar soil if you provide nutrients, water, sunlight and an atmosphere, which is true of any material that isn't plant poison. And even then, when it's been done, growing plants and actual soil from the Apollo missions, they have trouble they show signs of stress.

Benjamin Thompson

One thing I'd say though, I didn't think I'd ever say out loud in my life, is we need to talk about Neil Armstrong's poo. You mentioned carbon there Zach, and this is one of the things that I must confess, I mentioned to the rest of the Nature Podcast team, and I was like, 'you're not gonna believe this'. Now, you mentioned that the moon is carbon poor, comma, except...

Kelly Weinersmith

...except, yes, but the bags of faeces and vomit left behind after the Apollo mission. Those are probably the most concentrated sources of carbon on the Moon. But you also probably shouldn't collect them and use them in your garden because NASA thinks of them as like, heritage and things that still belong to us. So you get some people angry if you grew potatoes in Neil Armstrong's poop.

Zach Weinersmith

See that's a policy though it's not law. So technically, you could get that poop and grow stuff in it. But it is recommended against.

Kelly Weinersmith

Yes.

Benjamin Thompson

We need to unpack that. But let's pause on it for the time being. The other thing I noticed that you mentioned about the Moon, which makes it less than hospitable — and I've got it written down here in my notes — the regolith, or the soil, that makes up the Moon is essentially tiny electrostatic knives, which is less than ideal.

Zach Weinersmith

Well said!

Kelly Weinersmith

Yes. So it is, you know, it's like little jagged pieces of glass and dust and there's concern that if you breathe it in that it could scar your lungs and create something like stone grinders disease, and as you mentioned, it's electrostatic so it clings to everything, so you're gonna have these problems with trying to make sure that if you go outside, you don't bring it back into your habitat. It's also going to be a massive problem for your equipment because it's very abrasive. It's a problem.

Zach Weinersmith

There's like subtle stuff, like the suits they would wear on the Moon, the moonwalkers. They were mostly white. And part of that's to reflect the intense light because the Moon has two-week-long days. But when it can get coated with this regolith, and astronauts reported this, you know, it messes up that system, right, because the regolith is like plastery grey, right, so it's absorbing more heat than you had planned for. So there's just a lot of little subtle problems you have to remember, the total time people have walked on the surface of the Moon is under two weeks, we like we really don't have like an employee handbook built up.

Benjamin Thompson

But this annoying, like jagged dirt is an important part of our ability to survive on the Moon. So we don't know much about radiation in space, and how it impacts human bodies. And so most of the proposals we saw, required like a habitat that then is buried in like metres of this jagged dirt, because the radiation will hit it and not get down to your habitat.'The Moon obviously, well, it seems like there's ups and downs to it. But of course, I think a lot of folks are interested in the Moon as a jumping off point to Mars. And Mars has an atmosphere, not a very thick atmosphere, but it does have an atmosphere. And I think you make the point that technically, it has everything that humanity might need to survive. But as with so much of this book, there is a 'comma but' to that as well, not just in terms of getting there. But also in terms of once you do get there, what you would experience.

Kelly Weinersmith

So Mars has some of the same problems as the Moon, and in particular, it's exposed to the radiation that we get in space. That 1% atmosphere doesn't help that much. And it doesn't have a magnetosphere like we've got on Earth, which protects us from a lot of this stuff. So you're going to be exposed to radiation. But that 1% atmosphere is still enough for dust storms to whip up and cover the entire planet for sometimes weeks at a time. And when that's happening, your solar panels are y'know, not going to be super reliable, which we learned in The Martian. So you're gonna have to depend on like portable nuclear power plants and stuff. It also has that dirt that sort of sharp and you got to worry about breathing it in. But on Mars, you get the added bonus of 1% of that is perchlorates, which is a chemical that binds to your thyroid and messes up hormones, which we need for things like regulating heart-rate and blood pressure. I can hear the advocates now though saying, "But it's water soluble, you can just rinse it out". However, we bought a farm recently, and we grow food that we feed to our children. And if someone had said, "Well, there's endocrine disrupting hormones, but just rinse it real good first", I think we would have bought somewhere else. But it's got days, they're sort of Earth-like a little bit more than 24 hours. So that's nice, the temperature isn't so horrible, that 1% atmosphere dampens the temperature swings a little bit. And it's got a lot more water than you've got on the Moon. And that water is findable with varying degrees of effort just about anywhere on the planet. So you know, Mars does have a lot of stuff going for it, we might be able to live there, even if we were disconnected from Earth at some point, but it's going to be a big project.

Benjamin Thompson

So Moon, okay, yep, we could probably figure that out. Mars, well, okay, maybe. You also talk about space stations, which for you are out. But I think, obviously, that's the 'where' I suppose. But the people who live there or move there is super important because this enterprise doesn't work unless there are people there. You mentioned there that really a lot of the data we have on space, and certainly on being in places outside of Earth. It's really down almost to the minute or hours, I guess in terms of the Apollo astronauts. And if we're using the Apollo astronauts as, this is what we know about physiology and what have you, in heavy inverted commas an astronaut is not a 'normal person'.

Kelly Weinersmith

No, absolutely, they passed an incredible battery of physical and psychological tests. These are people who are way better than Zach and I, for example.

Zach Weinersmith

In particular.

Kelly Weinersmith

And you know, there were only a handful of missions that went out beyond Earth to the Moon and back, they were very short missions, like two weeks or something. But we do have decades of data from hundreds of astronauts that were orbiting the Earth, but they were within Earth's magnetosphere, so they don't really tell us anything about the kind of radiation you'd experience on the Moon or Mars. And they were in essentially zero gravity. So they're not experiencing the sort of like pull of gravity that our bones and muscles experience when we're down here on the planet. And we know that that's bad. We know that degrades bones, we know it degrades muscles, it looks like it also is bad for vision as fluid sort of shifts up and presses on your eyes and your nerves and stuff. But we don't know how like 40% gravity that you'd find on Mars is. Like maybe that completely makes all those problems go away. Or maybe those problems just sort of show up a little bit more slowly.

Benjamin Thompson

I mean, you are a scientist, Kelly, of course and your work relies on data, right, to test your hypotheses. So there really is an absolute lack of this in this endeavor.

Kelly Weinersmith

There is very little Yeah, so I mean, there's some things that we can learn that a two week trip by superhuman men is fine. We have done some experiments, the Japanese Aerospace organization has sent up these wheels that rotate and you can spin them up to simulate Moon and Mars gravity. And so we can get some handle on how partial gravity impacts rodents for sort of short term, but the data has not systematically been collected in a way that would make us feel comfortable going up there and saying, 'Okay, we are ready to have children here and expose them to space for their entire lives'. You know, the International Space Station did not go up with the explicit goal of preparing us for settlement. And so not surprisingly, we haven't been collecting the right kind of data for this question. And it are going to be difficult to collect quickly. It's going to take, you know, many years to get the data that we need.

Benjamin Thompson

So you've gone through some of the physical concerns there. What about the psychological or mental health strains that might be associated with this endeavor?

Zach Weinersmith

Yeah, yeah, yeah. So this was one of the hardest chapters for us to write was on space psychology, we had a version of it, that was like, literally 10 times longer, because there's so much there. But a big problem you face is the data is really hard to parse. It's often quite low quality. And so one reason is that just not a lot of people have gone I think, now we're up to maybe 700 astronauts, most of whom are middle-aged men. But also a big problem is that astronauts are liars. So one of the things we did for this book is we read just a ton of astronaut memoirs, you would be shocked how often they're willing to tell you about how they lied, like there was a guy who memorized the colorblindness test, like the dots, so he could cheat because he was colorblind. There were several people who cheated on the height tests, like one guy cheated by like standing up all night long before they were going to check him, so he would be as short as possible because you had to get under a certain height. One of our really good finds, we're reading this kind of obscure book of interviews with old cosmonauts, and there's a woman cosmonaut Ponomaryova, I think, she was the backup for Valentina Tereshkova, the first woman in space. And she said, she cheated the exams. So the deal is basically, there's is an old tradition goes back to aviation, that you never want to tell the truth to a flight surgeon, or a psych person because all they can do is ground you, right? They can't like make you extra on flight. All they can do is take away your privilege. So as a person trying to understand space psychology, you just cannot believe the data. Terry Virts, in a 2020 book, this is not just an old thing, he said he would put on a happy face whenever he had to talk to the psychiatrist, no matter what. And so the question becomes like, well, then what can we say about space psychology? Because people have this conception that maybe you'll go crazy up there. But the good news is we do have like maybe more reliable data from like submarines, from Antarctic bases. And the basic picture is people just, they don't go nuts on submarines, they don't go nuts in Antarctica. I mean, they are screened, they are screened less carefully than astronauts, because everybody wants to be an astronaut, and everybody wants to live on a submarine. So the basic picture is, it's probably all right. But and this is the important thing for settlement that doesn't get you off the hook. Because if it's all right, that means you just have an Earth rate of psychiatric problems, which on Earth we have infrastructure to deal with and which we won't have on Mars.

Benjamin Thompson

And what are some of the other key questions or big areas, I suppose, that need to be thought about in terms of having humans leaving Earth and going to live somewhere really, really far away?

Zach Weinersmith

A thing we're big on is we need these questions on whether you can reproduce in space, right. So we basically know nothing about this. There are lots of space station experiments that are pertinent to human reproduction. But they're things like there's an experiment with quail eggs, and there's one with lizards. And there's one with geckos, and there's a few with rats, and the results are kind of equivocal. Some seem to go fine. Some had like catastrophic problems. If those problems are due to space, we don't know it could have been random, the sample set is quite small. And where this really gets freaky, like usually when people talk about this, they talk about can you have birth in space, right. But of course, if you want to settle it, the baby has to grow up to have its own babies someday. And that requires you to get through all that awful stuff Kelly described, the hormone disruptors, the radiation, the lower gravity, all the way to adulthood without problems, and I think you can make a pretty good argument there, on its face reasons to suppose that you'll expect a higher rate than normal of birth abnormalities. And what's scary about that is you start talking about having that in an environment where there's not an infrastructure to help people. And sometimes space advocates are willing to just come out and say, well, we'll have to have a lower standard for valuable human life, we'll have to see what natural selection does, which, you know, is a nice thing to put in the sentence. But if you imagine what you're actually talking about it's horrific. And so when we talk about space ethics, you know, we kind of worry people are gonna roll their eyes like we're sort of pearl clutching about, you know, bad stuff happening in the abstract, but this is like real legit stuff. If you try to settle space without this knowledge of human reproduction. It is experimenting on children end of story, which no ethical system that I'm familiar with permits.

Benjamin Thompson

Right? Wow. I mean, where do you go from there? Skipping about a bit. One thing that struck me is how many people you would need to set up a base somewhere, right? Because not everyone isn't expert in everything, okay. You'll need people who've got carrying skills or engineering skills or whatever it is, right, medical skills, and not everyone has everything. And I know some research has been done to work out what is the number of folk you might need, and I will say the error bars are fairly wide on this one.

Kelly Weinersmith

I think for a self sustaining settlement, we found numbers as low as 100,000. And then as high as was it a billion?

Zach Weinersmith

Yeah billion, I think was the highest.

Kelly Weinersmith

It was a lot. And so this is for autarky, which is the idea that you could survive on Mars, all by yourself without needing anything from Earth. There's a lot of variability there, you can imagine, like, Okay, well, we're willing to live with fewer medical specialists and take that added risk that there won't be the person there, if you have, you know, a rare disease, who will be able to help you out. But you know, for genetic diversity, you need a lot of people. And we end up arguing that it would be ideal if we waited until we could send a lot of people up there all at once and know that they're going to be safe. And in addition to genetic diversity, there's a lot of economic benefits. So we did a lot of work studying company towns, because a lot of the people that you've talked to in the community will say, the first settlements are going to be company towns. And we were like, 'okay, well, then let's look into that', and it turned out that one thing that really makes life better in company towns is having mobility. So if you are in a job, and your boss is treating you awfully, being able to go to a different job is not only good for you, but it's also good for the people who are left behind, because this is like a way to tell the bosses, you can't treat us this way, if you want to retain your workers, you need to do better. So if you only have one settlement on Mars, you essentially have zero labour-mobility, because it will be way too expensive to go back to Earth. And there's no other options on Mars. And then other people will argue that 'well, the first settlements will be communes', also turned out there's a lot of turnover in communes. And a lot of different people who run communes will explicitly say, part of why our commune managed to stick around for so long, is because when there was a problem that people who didn't like our decision left, and that was like a pressure valve for us. And so for a lot of reasons, having a lot of people and a lot of options will make life better.

Benjamin Thompson

So working out what the optimal population size is, is tricky then, and I think you write a little bit about experiments and research that was done to work out what is a good space-based colony look like, and some of this has come from conservation biology, and folk who have tried to kind of — obviously we haven't got up to the millions — but do small scale experiments on Earth. And you wrote that it's tough to try and test out what it might be like to live somewhere far away. Because if there's no parallel, there's no payoff. Fear of death, it seems, is weirdly quite an important thing to consider when you're planning to leave Earth.

Kelly Weinersmith

Yeah, so we've we've read about a lot of simulations and analogs. And these are sort of setups that are sort of Mars, like in one or more ways. And it did seem to us like for some of them, for example, there's a facility in Utah, where when something breaks down, they drive into town to get the equipment that they need. Whereas of course, in Mars, that would be death, you'd be a goner. And so we feel like that's really important from a psychological perspective. And additionally, you know, if you're only running these experiments for like, two weeks, you're not really capturing how stressful it's going to be. If you are in a tin can with six people for two years, that's very different than meeting eight interesting strangers that you're going to hang out with for two weeks. Those are very different levels of psychological strain. And so there's some things you can learn from these. But in our minds, the most interesting experiments are the ones where not only are they sort of trapping people inside for a long time. But they're also trying to recycle things. So for example, Biosphere 2 in the 90s, was trying to create this closed-loop ecosystem where on three acres in the Arizona desert, they had this big glass dome, they were trying to provide all of the air cleaning things that needed to happen through the plants. So the plants would extract the carbon dioxide and produce the oxygen for the eight people living inside, they were trying to grow all have their own food, they were just trying to be completely self-sustaining and recycling everything. And they lost 10 to 16% of their body weight. They split into two hateful factions that were literally spitting on each other at one point, they had to pipe in oxygen, because they ran out of oxygen. And they had scorpions that accidentally got in, and they were the only species of scorpions in the US that's life threatening. And so there were there were some things that could have gone better. But on the other hand, you know, they they did learn a lot. And if the experiment had kept running, they maybe could have learned a lot more. And there are some other experiments like there's one in China called the Lunar Palace and they've done some really cool recycling experiments.

Zach Weinersmith

Yeah. And so, like, we're more interested in experiments like this, because the psych aspect which you mentioned, you know, some scholars will even say, we don't think this is, you know, these chamber studies are viable, because like, you can just leave.

Benjamin Thompson

If we can assume that we've decided where to go. We have the technology to get there. We know enough about what it'll do to us. Let's assume we pass those tests on, we're on our way to whoever it is — Mars, or the Moon, I suppose. The view that I would have, I think many people would have is that we'll be living under these kind of half sphere, geodesic dome type thing, right with cool suits and what have you, but it seems like architecturally, that isn't going to cut it. So if we assume with their what does this settlement look like? Does it depend whether they're on Mars or the Moon, are they vaguely the same? What are some of the trials and tribulations?

Kelly Weinersmith

I think a particularly epic version of a space settlement would maybe be in the lava tubes that you find on the Moon or Mars. So these are, these are like giant caverns, essentially, that were produced when lava was moving underground. And it's sort of solidified the external area. And so now because you're underground, the temperature swings are way less pronounced, so you've got more steady temperature, and that's good for equipment and for people. Also, because all of the regolith has been like solidified, you have less concerned with getting that dirt in your habitat. Additionally, if stuff is pounding the surface of the Moon or Mars, you know, now it's hitting the surface, but it's not hitting your habitat, and you've got some protection from radiation. So some of the cool proposals that we've seen include setting up habitats and maybe even trying to like, stick an airlock on the tube, so that you can walk around sort of outside quote, unquote, without a spacesuit on. And that sounds pretty awesome, I would watch that reality TV show for like an episode or two. But if you're going to be on the surface, your habitats are probably going to be buried in that regolith, because you're going to need to protect yourself from radiation, these beautiful glass domes that you see where people you know, watch the sunrise on Mars or whatever, that's probably not going to happen, you get roasted by the radiation.

Zach Weinersmith

Just to completely ruin the glass dome thing. And we talked about this a little bit. So people may have seen pictures of Biosphere 2, which is this, you know, giant 3.14 acre greenhouse, it's gorgeous. It's amazing. And it's sealed. One thing people don't notice is there are these two huge circular facilities joining it, which were called lungs, all they did was regulate pressure, right, because you have a greenhouse, you have a temperature difference on the inside versus the outside, which is really bad to have across windows to have a pressure differential buildup, they had to have these huge systems to regulate that. Well, on the Moon and Mars, you've basically got no pressure outside the window, and you've got some pressure if you want humans walking around inside the window, right? So why you would go through all the effort of building this sort of thing, when you could just put like a movie camera still of nature on the wall or something.

Benjamin Thompson

My first thought then is like, my vitamin D levels are dropping through the floor with no access to sunlight. So you need to be able to grow things in terms of food, what sort of things do you think the food on our outer-space base looks like?

Zach Weinersmith

Ideally, most of it is made on site. And so that's why we think experiments like Biosphere are really interesting. Probably, you're going to have some sort of intensive agriculture operation, probably you're going to have to be vegan. The least bad option, if you want some animal protein is probably insects. As a general rule, the bigger the creature, the more energy you need per calorie you get back out. One thing that's worth noting on that, by the way, is that it's going to take a lot of effort. So one of the findings across many studies of these closed -loop systems is that it's just a huge amount of work to supply your own mouth with food. On Biosphere, most of what they did with all of their time was just maintaining operations.

Benjamin Thompson

Towards the back of your book, you really investigate guidelines and ethics and stuff, regulations, which as I said earlier, at first knockings is like 'uh'. But it seems really important. And what nations are legally able to do, I think, is an interesting thing at the moment, because you make the point that in many ways, the Space Race in the 60s, was very much propaganda for the US and the USSR, so people were figuring it out from there, like the law was kind of made as it was going along. And in some cases, it hasn't hugely expanded since. Now, with the exception of Neil Armstrong's poo, which you mentioned earlier that potentially I'm not allowed to use to grow, whatever I want to use it to grow. It seems like there's ambiguity in who can do what and where.

Kelly Weinersmith

Yeah, so most of space law comes from 1967, when there was a treaty through the United Nations that goes by the name, the Outer Space Treaty. And that's the main governing document today. And from the standpoint of space settlements, the important things to know are that Article Two says you can't appropriate land in space. So you can't land on the Moon and say, 'This is our sovereign territory'. But what's unclear is what are you allowed to do with resources in space? So could you go to the poles of the Moon, which are where you can find water in the form of ice, and could you say, 'Alright, I'm starting a gas station, I'm going to turn this into propellant, and I'm going to sell it to other people with rockets who want to go to Mars'? And do you have a right to essentially burn into the vacuum of space, the few sources of easy to get water on the Moon. And that is unclear right now from the Outer Space Treaty, and so into this legal vacuum, we're getting some different interpretations. So the United States has consistently had the interpretation that going and claiming that the land belongs to you is one thing, but extracting and selling resources is very different that doesn't require the claim of sovereignty. So we have a right to go up there and extract and sell what we found. And the 2020 Artemis Accords came out through NASA and sort of had this statement and over 20 other countries including major spacefaring nations have signed on and so this interpretation seems to be sort of gaining traction. Notable countries that haven't signed that are also space powers include China and Russia. And part of that is because we're not really supposed to be cooperating with China in space because of the Wolf Amendment sort of separates NASA and space activities with China. But it does seem like maybe there's going to be this race, for the few places in space that are really good, particularly starting with the Moon. And at the moment, there's there's ambiguity about what you're allowed to do up there. So I mentioned there's places on the Moon where you can get ice water, those places also happen to be some of the best places to set up solar panels. So if you're on the equator, you need to have enough battery packs to get you through a two-week stretch of time where it's just night. But on the poles, if you stick your solar panels up on, like, stilts, you can get sunlight, something like 90% of the time. And so there are these very small regions that easily could be sort of captured by a company that sets up shop and then doesn't leave, where we could have some sort of conflict over territory.

Benjamin Thompson

And with so much of law interpretation, really is the key. So you can't say 'this is mine now'. But you can say 'I'm just resting here for a bit'. And that is within the scope of the frameworks as they exist. Is that right?

Zach Weinersmith

We would say it's right. I mean, there's always going to be a 'probably' with law, because there is this uncomfortable ambiguity. We talk about, like, say the US plunks base on Shackleton crater, which is one of these really premier locations, they cannot literally say 'this is the United States', but they could stay there for 50 years. And maybe during those 50 years, people set up like stuff that American citizens think of as important to them. Maybe at some point, there's an incident where some people die, and they're buried on the Moon, in that space, at which point, it's still not US territory. But it would be really controversial for someone to say you have to move because you're not allowed to claim territory. So you get into really uncomfortable stuff, which as you mentioned, was not the case in this space race from the 60s, which was really a race to do a stunt, that one person doing it only diminished its PR value didn't diminish other people's ability to do it.

Benjamin Thompson

And something that was interesting to me is that if something goes wrong, whose fault is it? Because there is an inherent danger to this? Right. So let's say that I, in the distant future, happened to be living on the Moon, and an accident happens, and I perish for whatever reason. It turns out, it's quite difficult to work out who's in trouble for doing whatever it is they did.

Zach Weinersmith

Yeah. So first of all, congrats on your awesome death. So Kelly mentioned, the governing document is the Outer Space Treaty, there were a couple more treaties done in the early 70s, which are basically elaborations. For your question, the important one is what's called the Liability Convention, essentially, like if someone kills you in space, the state that is backing the killer, or the manslaughter is liable. And that's typically going to be determined by where the vehicle that got there launched from or the nationality of the person who did it. So there is law that is pertinent to your death on the Moon.

Kelly Weinersmith

And perhaps more pertinent. So Starlink is a satellite constellation that provides Internet back here on Earth, it was put up by SpaceX. And in the Starlink Terms of Service, it states that if a settlement is established on Mars, it will not be beholden to the laws of Earth. And that straightforwardly breaks the Outer Space Treaty, like if Elon Musk is the one who's sending those people, then they are absolutely the responsibility of the United States, international law will follow those earthlings to space. So we talk to people often who say something to the effect of well, who can stop Elon Musk once he gets out there? And the answer is, it would probably be the United States's has responsibility to say something to the effect of 'we are giving you no more licenses to send your rockets to Mars, and you're going to need those resupply vehicles'. And so international law does allow for some control of behavior, even when people go out into space.

Benjamin Thompson

It seems like essentially, what you're calling for in this part of the book is more and more relevant, you know, bureaucracy and laws to remove some of this ambiguity. But I wonder, because calls for this, as well as calls for data, right — there's just a lack of data — on all sorts of things is anything you've laid out there. It rather seems at odds with the kind of swashbuckling like, let's just just go and figure it out, like, this will be fine — don't worry about it, let's just go. Did you find that you were at odds with that, and that people you spoke to, you know, you kind of clashed heads with do you think?

Kelly Weinersmith

Oh, yeah, no, absolutely. There are a bunch of people who really believe that going out into space is going to benefit Earth in some massive way. So it could be the resources are going to help bring people out of poverty. All of this extra territory is going to mean we don't have to fight for territory on Earth anymore. So we're going to have fewer or maybe even no wars, and that people like Zack and I are thwarting this super-awesome, peaceful, prosperous future. We are not convinced by arguments about resources and space lifting us out of poverty, or increased territory is going to reduce the likelihood of war to us war seem to be about specific territory. So yes, there are people who are very upset that we are essentially proposing a slow-moving, bureaucratic non-swashbuckling future. But we feel like if that increases safety on Earth, that's worth it.

Benjamin Thompson

I'm gonna think we kind of need to bring this home, really. I mean, a two-part question here. One: is this a good idea? And I'm kind of getting a sense that there's a bit of a maybe aspect to it from you. And two: if this was to be done, what does a good go at it look like? Like, how could this be done, well, what is an optimal — I say, escape from Earth — but leaving that to go somewhere else looking out? Do you think?

Kelly Weinersmith

Well, I think it could be done well if it's done carefully. And so to me carefully would involve, you know, maybe starting out with an international research station on the Moon, where we all work together to get some of the data that we need to figure out how safe this is, while at the same time a bunch of lawyers are working on sort of the rules for resource extraction and who was allowed to set up where, and then we go out to Mars, maybe a couple decades from now, and a bunch of people go out there at once. And we make sure that we could have people move in between societies, and you know, they'd have some mobility and some options. What do you think?

Zach Weinersmith

You can believe that having a space settlement is just sort of objectively amazing and wonderful, and we should probably do without buying into silly things, like the idea that it will somehow rejuvenate all Earth culture, which is, by some means gotten bad, or that it will make everybody rich forever, or that it will be like a permanent source of perfection of humanity or any of this nonsense. You should probably even reject the idea that it's going to make money. And when all that's done, all that's left is this idea that what we should do, because it's just really cool, and it would be a total bummer that there's a whole universe and we're just staying here. And I think that's okay. And the things we have to do to work toward it are objectively just sort of interesting and wonderful. It's just in order to get to Mars, we have to first survive long enough to have the technology to do it. And so that means you cleaning up our house down here for a long time. Unfortunately, perhaps.

Benjamin Thompson

If somebody offered you both ticket tomorrow. Like, have you spoken about this situation between you like, is there disagreement between you?

Kelly Weinersmith

No.

Zach Weinersmith

No we're cowards, maybe one, you know, a couple of million people have gone and like there's a McDonald's?

Kelly Weinersmith

I study wasps and I would say until all the wasp species have been discovered and described, I see no need to go to Mars. There's a lot of work left to be done here.

Zach Weinersmith

It's probably a unique standard.

Kelly Weinersmith

Yeah, it's probably a me thing.

Benjamin Thompson

Well, let's leave it there. Then. All this have to say is Kelly and Zack Weinersmith, thank you so much for joining me today.

Zach Weinersmith

Thanks. It's been lovely.

Kelly Weinersmith

Yeah, thanks for having us. It was a lot of fun.

Benjamin Thompson

Kelly and Zach Weinersmith there. Their book, 'A City on Mars' is out now. That's it for episode seven of Nature hits the books. If you have any feedback on the show, why not ping us an email to podcast@nature.com with the subject line 'nature hits the books'. Otherwise, look out for the next episode later in the year. The music used in this episode was called to clarity by Airae via Epidemic Sound and Getty Images. I'm Benjamin Thompson. Thanks for listening.