TIL: How to Transform Mars into Our Second Home | Today I Learned

Hey there, would you like to live on Mars? That's a garbage idea! If you try to go out there right now, you would simultaneously freeze and choke to death.

I'm Brendan Mullin, an emerging explorer with National Geographic and an astrobiologist. I'm here to tell you to wait. Mars is almost one and a half times as far away from the Sun as Earth is, and its atmosphere is about a hundred times less dense than our own. The average surface temperature on Mars is something like minus 81 degrees Fahrenheit.

But as humans, if we're good at one thing, it's drastically changing our environment. So what if we can make Mars more like Earth? There's an idea that's been around for a hundred years or so in science fiction. It's called terraforming. It basically means we want to take whatever planet and turn it into Earth.

To think about terraforming, well, imagine Mars is a glass bowl like this. We want to take this Mars terrarium and thicken up its atmosphere a little bit. There are a couple of options. We could take asteroids and comets and send them hurtling into the Martian atmosphere and have them smash into the polar ice caps.

When you throw these asteroids and comets into these poles, they'll cause them to sublimate, turning directly from solid into a gas. Hopefully, that will pump enough carbon dioxide gas into the atmosphere. Or, you could take giant space mirrors that will focus the sun's rays onto the polar ice caps, causing basically the same effect.

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I've got to keep your space bears clean. Or, and this is a fun option too, you can build a whole bunch of giant factories on the surface of the planet that produce a lot of CFCs, chlorofluorocarbons. You know, the things that we outlawed in the 80s because of all the hairspray we were using.

So now we've got a thicker, warmer atmosphere. We've got a lid for our Mars jar here, but it's still basically an atmosphere of poison. No matter if there's anything that will magically turn carbon dioxide into something like oxygen for us to breathe—plants!

Now we have plants. All we need is time. These plants, on their own, will take carbon dioxide from the air and turn that into oxygen that we can breathe. Mission accomplished. We terraform Mars, right? Kind of.

There are a couple of big things we need to think about. The first one is it’s going to be really expensive, and it’s going to take a long time. Another problem, which is probably the worst, is that Mars doesn't have a magnetosphere, a protective magnetic shield like the Earth does.

Solar wind, the charged particles that come off of the Sun, slam into that atmosphere and will strip away atoms and molecules. Fins, over a long enough period of time, we're going to have to start this terraforming process all over again.

Let's say we could solve all those problems and terraform Mars anyway. We made it so that the next generation of astronauts could live there—no problem. Would you want to go? Mars was warmer and wetter and even had an ocean that covered the entire northern hemisphere. So where did that ocean go?