When Earth’s sky turns red and the clouds become flaking black soot, when the air chokes human animals like a gulp of vaporized chlorine and the plants are pulled from their roots by the wind—people will wonder where we can go. They will consider a better time or a better place, and they will do what humans do. They will look for any way to survive. But will they actually go to the equally uninhabitable dunes of Mars?
Many conversations concerning what humans will do when Earth becomes less habitable, whether due to climate change or a series of manmade disasters, become conversations about leaving Earth for another planet. Mars, a planet of similar size to Earth and one humans have been able to reach, is often brought up as an option. Many experts don’t see abandoning Earth as a necessity, but if Earth does become uninhabitable by the standard definition, we could easily use the same technology we would use to live on Mars to just stay on Earth.
“I do not think we will need to abandon the planet any time soon,” says Bas Lansdorp, co-founder and CEO of Mars One, the nonprofit organization planning to send humans to Mars. Lansdorp sees Mars as a new frontier—something to help expand human knowledge and further our civilization. “I hope that going to Mars might actually avoid that situation from occurring on Earth.” He says if the Earth is ruined, with toxic air and water and natural resources running out, the technology we use on a Mars colony could be our only hope. That might include living quarters that are protected from the elements, sealed greenhouses, or any number of other methods of maintaining protection and sustainability from a harsh external environment.
“If humans on Earth see how tough life on Mars is, because of the difficult conditions on the planet, I think that will convince humans to be more careful with their own environment—with their own planet,” says Lansdorp. In his mind, going to Mars could help humanity realize how good things are on Earth, and it may be the crux for deciding to try and maintain that level of quality.
There are many issues with attempting to survive on Mars that could teach humans how to survive on a theoretically damaged Earth of the future. One is radiation. On its trip to Mars between 2011 and 2012, the Mars Science Laboratory recorded levels of radiation 100 to 1,000 times higher than what we experienced on Earth. The radiation is not just coming from the sun, which is radiation we’ve learned how to block to an acceptable extent, but galactic cosmic rays (GCRs) that come from other sources in the Milky Way. GCRs are incredibly difficult to shield from, and technology still needs to be developed to do this more effectively.
The thin atmosphere of Mars would provide some shielding once the explorers arrive, but structures will still have to be built to further block the radiation. These structures would help prevent serious radiation sickness in the short-term and explorers dying from cancer on a longer timeline. Mars One’s website says that the level of radiation people would be exposed to on the way to Mars is acceptable, and Lansdorp says that covering the habitat on Mars with meters of soil from the planet will block much of the radiation from hurting explorers. Essentially, the Mars explorers would live in structures that are partially underground and covered with soil to absorb the radiation, which could also be done on Earth.
Mason Peck, an associate professor at Cornell University and former NASA chief technologist, also sees promise in the concept of building soil-covered living structures on Mars. He says the concept could help humanity if our own atmosphere is ever weakened to the point of it letting in dangerous levels of radiation. “On Earth, [living partially underground] is a very sustainable way of surviving,” Peck says. “It could be that in the future we learn something about how to survive on Mars, living underground, and we could use the same technologies for creating more sustainable homes on Earth.”
Peck claims humans will learn a lot about how to properly live on a planet with limited resources by going to Mars. Once we’ve learned from Mars, we might not ever need to live there in large numbers. “There are a lot of people on Earth who don’t like the idea of having to scale back—rather than living in a large, rambling house, just living in an apartment or a prefabricated home—but that is how we have to live on Mars,” he says. “We don’t have the means to take mansions with us to Mars.”
Beyond not having a bowling alley in your house, Peck says there are simpler sacrifices humans would have to learn to make if Earth becomes less rich in available resources. One thing people in the developed world take for granted on Earth is a huge diversity of foods to choose from, and going to Mars may teach humanity that such a bounty of options is not entirely necessary.
“There are millions of people on Earth who have extremely limited options for what they can eat,” says Peck. “There are plenty examples of people on Earth making due with very little.” Peck believes that whether we’re talking about maintaining life on Earth or learning to survive on Mars, having four kinds of avocados to choose from may not be a priority. “I think we are living quite beyond our means here,” he says. Peck also believes the still developing methods for 3-D printing food, using chemicals and things like soy beans or fiber, could prove useful in future scenarios where food is more scarce.
We can also learn from the critiques that say a manned mission to Mars is foolhardy from the outset. A recent analysis by MIT, for instance, claimed the amount of crops necessary to sustain humans on Mars would produce too much oxygen and suffocate the explorers.
“To sustain astronauts over the long term would require about 200 square meters of growing area, compared with Mars One’s estimate of 50 square meters,” the paper says. “If, as the project plans, crops are cultivated within the settlers’ habitat … they would produce unsafe levels of oxygen that would exceed fire safety thresholds, requiring continuous introduction of nitrogen to reduce the oxygen level. Over time, this would deplete nitrogen tanks, leaving the habitat without a gas to compensate for leaks. As the air inside the habitat continued to leak, the total atmospheric pressure would drop, creating an oppressive environment that would suffocate the first settler within an estimated 68 days.” Peck believes these kinds of analyses are unable to extrapolate the ingenuity that can come when problems arise along the way.
“It’s a pretty straight-forward thing to get rid of oxygen,” says Peck. “You could light a match, for example, or you could breathe it. You could combine it with hydrogen to make water. There are actually many, many ways to oxidize chemicals for the benefit of the astronauts, and I think it’s a little naïve to think that simply because oxygen is produced that you can’t do anything else with it.” He says he believes these kinds of analyses are important, but he also thinks they should give engineers and innovators a little more credit.
There is at least one more factor that does need to be addressed before going to Mars. “One of the big unknowns is the response of the human body to a one-third or one-half gravity environment, which Mars represents, with very little atmospheric pressure,” Peck says. NASA has observed how bodies are affected in the International Space Station and addressed what concerns they can, such as the weakening of bones and muscles, but there are still anomalies that are hard to address to this day. “There are probably going to be issues that arise medically for the people on Mars that we don’t know how to fix,” he says.
It’s nice to think that splitting up the population between two planets would help take the pressure off of Earth that comes from there being so many people on the planet, but Peck says we need a much easier and quicker way to get to Mars than we currently have for that idea to be useful. “Think of how many people are born—one every eight seconds or something,” he says. “We’re not going to be sending one new person to Mars every eight seconds.”
Mars may or may not be a place where a consistent and large population of humans live any time soon, but visiting the planet and observing how life works there could greatly impact life on Earth. It seems extremely unlikely Mars would ever be more habitable than Earth, but it’s possible the planets could one day be more similar than different. It might not be comfortable or fun to stay on Earth in such a situation, but we could survive here with the technology we’re developing. Mars could soon show us what just barely surviving is really like. Visiting a desert always makes you appreciate an ice-cold glass of water.