Composition of air

So... do you think we'll be able to live on Mars someday? Hmm. Maybe. Only a few little glitches to sort out...

But let's assume... we can at least get ourselves there! But how do we breathe? Do we bring air with us from Earth? Or we make our own when we get there!

HA HA! And where do we find the INGREDIENTS to make AIR! Well, first we need oxygen, or we'd die for sure!? Yes, that's right. One fifth of the air in the atmosphere back home on Earth is oxygen.

You can actually breathe pure oxygen, but only if you have a much lower air pressure than normal, or you'd damage your lungs. And if the air was 100% oxygen, things would catch fire much too easily. 300 million years ago the oxygen content of the Earth's atmosphere was as high as 35%. And traces in the rocks show there were a lot more wildfires then. And...

Nitrogen? Why do we need this? Nitrogen is the gas that makes up most of the atmosphere on Earth - almost four-fifths. It is not really necessary for us, other than to dilute the oxygen. Nitrogen is a stable substance that is not eager to form chemical compounds with other elements, so almost all the nitrogen on Earth is found as a gas in the atmosphere.

Nitrogen and oxygen together constitute 99% of the air, so now your mixture is almost right. You can take your helmets off. Wait, Michael! Just as we need oxygen, plants need a gas, too: carbon dioxide. It,s only 0.04 percent of the air, but that's enough.

Release a little from the tank so the pot plant can be happy too! Actually, we wouldn't need to bring carbon dioxide in a tank to Mars, because we make it naturally in our bodies and breathe it out. Now less than one percent is missing, if you want to duplicate the air mixture found on Earth. And the gas you have in the fourth tank is: argon! Argon is a noble gas - which means that it's not eager to react with other substances.

And just like nitrogen, almost all argon is in the atmosphere rather than in chemical compounds. And now we've added the last one-percent of the air! Argon is not necessary for us, so do we don't really need to carry it with us. In fact, argon is being created all the time by the radioactive decay of potassium, found in the Earth's crust. We have potassium in our bodies as well.

Each person emits several thousand argon atoms per second. That's that! Now you can breathe here on Mars, too. The air is exactly the same as at home on Earth, with about: 78% nitrogen, 21% oxygen, 1% argon and a tiny bit of carbon dioxide. Just one more thing.

That air that you've mixed will run out of oxygen. The more you breathe, the more oxygen your bodies use, and the more carbon dioxide you will exhale. So if you plan to stay there a while, you need to figure out a way to get rid of carbon dioxide and produce fresh oxygen. Plants take in carbon dioxide and replace it with fresh oxygen! Brilliant!

Though you'll need to take a few more plants with you... There you go! Now you'll have oxygen so you can survive. Just remember to keep the window closed, so your valuable air doesn't escape! Maybe we shouldn't tell them that they didn't need to bring any oxygen at all - because in fact they could have made their own oxygen from the water ...

which is already here on Mars. But... that's another story!