Could people breathe the air on Mars? – The Conversation

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Could people breathe on Mars? Jack J., age 7, Alexandria, Virginia

Lets suppose you were an astronaut who just landed on the planet Mars. What would you need to survive?

For starters, heres a short list: Water, food, shelter and oxygen.

Oxygen is in the air we breathe here on Earth. Plants and some kinds of bacteria provide it for us.

But oxygen is not the only gas in the Earths atmosphere. Its not even the most abundant. In fact, only 21% of our air is made up of oxygen. Almost all the rest is nitrogen about 78%.

Now you might be wondering: If theres more nitrogen in the air, why do we breathe oxygen?

Heres how it works: Technically, when you breathe in, you take in everything thats in the atmosphere. But your body uses only the oxygen; you get rid of the rest when you exhale.

The Martian atmosphere is thin its volume is only 1% of the Earths atmosphere. To put it another way, theres 99% less air on Mars than on Earth.

Thats partly because Mars is about half the size of Earth. Its gravity isnt 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, thats 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; its 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.

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.

Without question, Mars is an extreme environment. And its not just the air. Very little liquid water is on the Martian surface. Temperatures are incredibly cold at night, its more than -100 degrees Fahrenheit (-73 degrees Celsius).

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 Earths surface. Many of those places have extremely hot or cold temperatures, almost no water and little to no oxygen.

And even if life no longer exists on Mars, maybe it did billions of years ago, when it had a thicker atmosphere, more oxygen, warmer temperatures and significant amounts of liquid water on the surface.

Thats one of the goals of NASAs Mars Perseverance rover mission to look for signs of ancient Martian life. Thats why Perseverance is searching within the Martian rocks for fossils of organisms that once lived most likely, primitive life, like Martian microbes.

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 theyll need to fly back to Earth. The more oxygen people are able to make on Mars, the less theyll 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, youll be an adult and maybe one of the first to take a step on Mars.

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Could people breathe the air on Mars? - The Conversation