Can we make an artificial Earth-like atmosphere on Mars?

Short answer: Mars has an atmosphere, but it’s about 170x thinner than earth and it’s 96% carbon dioxide, making it kinda shitty for life, and we’re probably not changing this any time soon.

Long answer: Think about what an atmosphere is. It’s an razor thin envelope of gas that wraps around the surface of a planet. There’s no way to fake that. You don’t want an artificial atmosphere, so much as you are actually asking for a real bona fide atmosphere.

So what are we working with? Mars’ atmosphere is primarily CO2, so that’s a bit of a problem. Carbon dioxide is toxic to people in large amounts, so people will have to stay in doors. Additionally, air pressure is low, about half a percent of the atmospheric pressure on earth. There’s two ways increase the air pressure: add a lot of gas so the atmosphere gets a lot heavier and presses down harder at the surface level, or adding a lot of mass to the planet so that it will have a stronger force of gravity on the air, pulling down harder on the gas. I guess I forgot to mention that these aren’t really feasible. Mars’ atmosphere current has a mass of 2.5 × 1013 kilograms. This is about 1% the mass of Mt Everest. Since the mass of the planet is probably harder to change than the mass of the atmosphere, we’d need to increase the mass of this atmosphere by about 200x in order to even get close to the air pressure in the Himayalas (which is way less than sea level). Good luck getting 2 Mt Everest’s worth of gas onto Mars.

But what if we wanted to make Mars habitable? Well there’s a large science fiction literature about this idea, called terraforming. Terraforming involves processing the natural atmosphere of a planet or moon into one that is more earth like. In the case of Mars, you would want to add green house gasses to warm the planet.

Possible mechanisms include:

  1. Your first though might be to set up solar panels that will use the energy they generate to break the Martian CO2 atmosphere into carbon and oxygen. But CO2 is really stable and carbon needs something to bond with, and if this was so easy, why not do it on earth and solve global warming/climate change?
  2. Put a satellite with a mirror in orbit to focus light onto the polar ice caps, melting them. The polar ice caps are mostly dry ice, which if converted to gaseous CO2 could raise the atmospheric pressure. Unfortunately, you’ll need a really fucking big mirror to even make a dent. Annual difference due to solar weather will make more of a difference than any satellite we could currently afford to build and send to Mars.
  3. Dandridge Cole and Donald Cox suggested bringing in large amounts of ammonia from comets to serve as green house gases to melt the polar ice caps. But how do you get them there? It’s hard enough getting people to the ISS, let alone doing astronomical construction projects.

Remember, the sum of humanity has been pumping carbon dioxide into the earth’s atmosphere for the better part of 200 years, and the effects have been slow to appear, so slow that’s it’s still hard to convince Americans it matters. So now how do you get a small team of scientists to do it on a planet we haven’t even set foot on yet?

So people on Mars? Sure, might be possible in our lifetime, but they’re not going to go frolicking in the rust fields with their shoes off any time soon.


 

 

asked by /u/jzand219

cover image credit: NASA via Wikimedia Commons


 

 

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