Could people breathe the air on Mars?

Authors
Disclosure statement
Phylindia Gant is a student collaborator on the M2020 rover. She receives funding through the University of Central Florida's NASA Florida Space Grant Consortium. She is a first year Geology PhD student at the University of Florida.
Amy J. Williams receives relevant funding from NASA's Mars Science Laboratory rover and M2020 rover Participating Scientist Programs, as well as through the University of Central Florida's NASA Florida Space Grant Consortium and Space Florida, and the Florida Space Institute. She is an assistant professor of Earth & Planetary Science at the University of Florida.
The air on Mars
The Martian atmosphere is thin – its volume is only 1% of the Earth’s atmosphere. To put it another way, there’s 99% less air on Mars than on Earth.
That’s partly because Mars is about half the size of Earth. Its gravity isn’t strong enough to keep atmospheric gases from escaping into space.
And the most abundant gas in that thin air is carbon dioxide. For people on Earth, that’s a poisonous gas at high concentrations. Fortunately, it makes up far less than 1% of our atmosphere. But on Mars, carbon dioxide is 96% of the air!
Meanwhile, Mars has almost no oxygen; it’s only one-tenth of one percent of the air, not nearly enough for humans to survive.
If you tried to breathe on the surface of Mars without a spacesuit supplying your oxygen – bad idea – you would die in an instant. You would suffocate, and because of the low atmospheric pressure, your blood would boil, both at about the same time.
Billions of years ago, Mars’ Jezero Crater hosted an ancient lake.
Life without oxygen
So far, researchers have not found any evidence of life on Mars. But the search is just beginning; our robotic probes have barely scratched the surface.
But plenty of organisms on Earth survive extreme environments. Life has been found in the Antarctic ice, at the bottom of the ocean and miles below the Earth’s surface. Many of those places have extremely hot or cold temperatures, almost no water and little to no oxygen.
That’s one of the goals of NASA’s Mars Perseverance rover mission – to look for signs of ancient Martian life. That’s why Perseverance is searching within the Martian rocks for fossils of organisms that once lived – most likely, primitive life, like Martian microbes.
Do-it-yourself oxygen
Among the seven instruments on board the Perseverance rover is MOXIE, an incredible device that takes carbon dioxide out of the Martian atmosphere and turns it into oxygen.
If MOXIE works the way that scientists hope it will, future astronauts will not only make their own oxygen; they could use it as a component in the rocket fuel they’ll need to fly back to Earth. The more oxygen people are able to make on Mars, the less they’ll need to bring from Earth – and the easier it becomes for visitors to go there. But even with “homegrown” oxygen, astronauts will still need a spacesuit.
Right now, NASA is working on the new technologies needed to send humans to Mars. That could happen in the next decade, perhaps sometime during the late 2030s. By then, you’ll be an adult – and maybe one of the first to take a step on Mars.
See what a human mission to Mars would be like.
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