Matt Damon made it look way too easy.
That was the problem with The Martian, the Oscar-nominated scifi movie that saw Damon marooned on Mars after his departing crew mistakenly thought him dead. Sure, he had to do a bit of work, but most his time was spent munching potatoes, making cool home videos and listening to god-awful disco music while everyone on Earth mobilized themselves to go get him. It wasn’t hard to imagine ourselves in Damon’s place, which is why the movie was so much fun. All we’d need is a little science knowledge, a willingness to spread our own shit around as fertilizer, and we’d be fine.
Well, no. It’s true that humans could, in theory, survive on Mars. Getting us there is entirely possible. It’s just extremely difficult, would cost a staggering amount of money, and would expose us to things that may (or may not!) kill us. Actually keeping us there once we’ve arrived? Establishing humans on Planet No. 2? You’re dealing with a difficulty level greater than most people can even imagine.
Let’s start with the simplest thing of all: walking around. If we lived on Mars, we couldn’t go outside. Ever. Mars not only lacks rather essential things like oxygen and survivable temperatures, it also has an atmosphere that stops very little of the solar radiation that our own benevolent atmosphere is so good at repelling. And since Mars is closer to the sun than we are, there’s a lot more of it - a fact that The Martian conveniently forgot to mention.
Establishing humans on Planet No. 2? You’re dealing with a difficulty level greater than most people can even imagine.
Matt Golombek is a planetary geologist and research scientist who has been working at NASA’s Jet Propulsion Lab for three decades, helping to operate the Mars rovers and select landing sites. He’s a cheerful, amiable guy who spends a lot of time considering the many wonderful and inventive ways that Mars would murder us. “The temperature and pressure of the atmosphere are so cold and so low that liquid water is unstable,” he says. “Any exposure to that environment by anything living would be instantaneous death. You need to create an environment that has a much thicker atmosphere. The current atmosphere on Mars is carbon dioxide so it’s not breathable by humans - you need an oxygen atmosphere at dramatically higher pressure, and you need to warm it up dramatically just to have liquid water. Those are the two biggest things.”
So, we need a place to live - a hab, as The Martian called it. There are a few ways we could pull this off. We could construct a pressurized hab on the surface, then pile dirt on top of it to block off the radiation. Or we could go underground, using the bedrock to do the job. Either way, we have a problem. You can’t use local materials - we’re not building mud huts here. If we create a hab on the surface, we have to bring it with us. If we bury ourselves underground, we have to have earth-moving equipment and infrastructure to stop it all coming down on our heads, and again, we have to bring it all with us.
Doing this is possible, but hideously expensive. The Curiosity Rover, now diligently patrolling the plains of Aeolis Palus, had a price tag of around $2.5bn. This for something the size of an economy car. Imagine the cost of getting us, our hab, and our earth-moving equipment all the way over there.
And even if we did, the gravity might kill us before the radiation does. Despite being a huge planet, Mars has around a third of Earth’s gravity. “That has medical issues for people,” Golombek says. “With [astronauts] on the International Space Station, there are clear medical effects from being in weightlessness. They put them on treadmills, and they work them hard, but what prolonged endurance to lower gravity means medically, I don’t think we know yet.”
Not all planetary scientists think this will be a problem, however. Kevin Grazier is a former JPL guy who worked on the Cassini Probe we sent to Saturn, and who now works in the entertainment industry - conveniently, at the time of writing, he’s shopping a TV pilot about Mars colonization. Grazier says he doesn’t believe gravity will cause us any major problems.
And even if we did, the gravity might kill us before the radiation does. Despite being a huge planet, Mars has around a third of Earth’s gravity.
“As long as you have some gravity, bone loss is minimized,” he says. “You lose about 5% of your bone mass when you go into space, and it doesn’t seem to matter how long you go for. I don’t think it will be an issue. 40% gravity is quite a bit, and it should mean you weigh just under half of what you weigh now, but I don’t believe that will lead to bone loss.”
If gravity and radiation and a deadly environment don’t kill us, a lack of water might. Food is easy - process the soil to remove toxins, add some fertilizer and seeds, which, again, you’ll need to bring with you, and you’re good to go. But water? That’s tricky. The easiest solution is to use Mars’ massive ice deposits (Hey! Something we don’t have to bring with us!) but you still have to have the equipment to melt it all down (Aw.)
“You have to figure out how to get the water to the concentrations that you need,” says Golombek, “and then you need to make liquid…That needs a lot of power, and a way to mine it. There are places on Mars at the higher altitudes that have ice, but it’s not like you poke a straw down there and just suck it out!”
But here’s the really interesting thing. All of this is possible. Tough, expensive and time-consuming, but possible. “I’m not as conservative as Matt is,” says Kevin Grazier. “I think it’s doable, and I think it’s been doable for a long time. What we lack more than anything else is the will. The will to risk human lives, and to sign on the bottom line for a wad of money.”
Let’s go full scifi. Let’s say that Mark Zuckerberg, Carlos Slim and Bill Gates teamed up with Russia and China and the US, and we decided to not only send people to Mars but start trying to make it more hospitable for ourselves, long-term. What if, in other words, we tried to terraform it?
“I think it’s doable, and I think it’s been doable for a long time. What we lack more than anything else is the will. The will to risk human lives, and to sign on the bottom line for a wad of money.”
Again: possible. Dauntingly difficult, but possible. After all, human beings have fundamentally changed the climate of Earth in a few short centuries. If there were enough of us, over a long enough time period, we could, in theory, make Mars habitable. We won’t be setting up giant atmosphere-adjusting machines or anything, but we could make a good start.
Of course, it’s not that simple. “I think there are moral and ethical questions about whether we should do that before we know whether there is life on Mars or not,” Golombek says. “We screwed up our own planet, and now we’re going to go and screw up theirs?”
It’s an interesting point. Colonizing and possibly terraforming Mars would be the biggest thing we as a species have ever done. Doesn’t it make more sense to try fix the existing, perfectly good planet we have already? And here’s where things get a little surprising, because despite the cost, despite the immense difficulties involved, both Golombek and Grazier think we should go to Mars. More than that: they give it a resounding thumbs-up.
For Golombek, it serves a deeper purpose. “You can ask a compelling science question by going there,” he says. “There is clear evidence that liquid water existed on the surface of Mars, when life got started here on Earth. It’s almost a theological question: what does it take to form life? Do you just need stable liquid water, or do you need a gazillion-to-one occurrence? Are we an accident of the highest order, or will life form anywhere? Those are compelling enough questions to certainly send robotic spacecraft, and maybe even send people. Whether we’re going to go and colonize it and call it a second home is a different question. That has to do with what happens here on Earth, and you’re talking about something over a much longer time scale.”
Kevin Grazier says that danger and difficult shouldn’t necessarily stop us from going. “We’re going to lose people, and I think we’ve forgotten that,” he says. “In 1999, we lost two [unmanned] missions. One was $125m, the other was $165m. Those are cheap missions. I don’t mean to sound dismissive, but that’s chump change. There are aerospace firms that can’t run for a day on that kind of coin.
Colonizing and possibly terraforming Mars would be the biggest thing we as a species have ever done. Doesn’t it make more sense to try fix the existing, perfectly good planet we have already?
“When those missions are lost, you get a public outcry: think how many people you could feed on that amount of money. Forget about how most of that money is spent on people rather than hardware, in terms of those who design and operate the spacecraft. Right now, what we need to do is sell the American public on the idea that it’s worth going to Mars.”
It’s something that NASA is trying very hard to do. Curiosity and the Mars Atmosphere and Volatile EvolutioN (MAVEN) probe are already up there. We’re sending another rover up in 2020. NASA is developing a new Space Launch System rocket to get us there in a more efficient way, and although the Chinese hardly ever reveal their intentions, you can bet they’re thinking about it too. We may not get to be disco-loving, potato-eating Martians in our lifetimes, but it’s a good bet that our descendants - maybe close, maybe distant - will be.
The Martian is nominated for 7 Oscars including Best Picture, Actor in a Leading Role (Matt Damon), Adapted Screenplay (Drew Goddard), and Visual Effects
Rob Boffard is a science fiction author. His latest book, ZERO-G, is out now. robboffard.com
Matt Golombek is a planetary geologist and research scientist with NASA’s Jet Propulsion Lab. science.jpl.nasa.gov/people/Golombek/
Kevin Grazier is a planetary physicist, NASA consultant, author, and science advisor for several television series and movies, most notably Battlestar Galactica and the film Gravity