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Saturday, October 16, 2021

Terraforming Mars in 3 Simple Steps

[This is a transcript of the video embedded below. Some of the explanations may not make sense without the animations in the video.]


We have made great progress screwing up the climate on this planet, so the time is right to look for a new home on which to continue the successes of the human race. What better place could there be than our neighbor planet Mars. It’s a little cold and a little dusty and it takes seven months to get there, but otherwise it’s a lovely place, and with only 3 simple steps, it can be turned into an Earthlike place or be “terraformed” as they say. Just like magic. And that’s what we’ll talk about today.

First things first, Mars is about one hundred million kilometers farther away from the Sun than Earth. Its average temperature is minus 60 degrees Celsius or minus 80 Fahrenheit. Its atmosphere is very thin and doesn’t contain oxygen. That doesn’t sound very hospitable to life as we know it, but scientists have come up with a solution for our imminent move to Mars.

We’ll start with the atmosphere, which is actually two issues namely, the atmosphere of Mars is very thin and contains basically no oxygen. Instead, it’s mostly carbon-dioxide and nitrogen.

One reason the atmosphere is so thin is that Mars is smaller than Earth and its mass is only a tenth that of Earth. That’d make for interesting Olympic games, but it also makes it easier for gas to escape. This by the way is why I strongly recommend you don’t play with your anti-gravity device. You don’t want the atmosphere of Earth to escape, do you?

But that Mars is lighter than Earth is a minor problem. The bigger problem with the atmosphere of Mars is that Mars doesn’t have a magnetic field, or at least it doesn’t have one any more. The magnetic field of a planet, like the one we have here on Earth, is important because it redirects the charged particles which the sun constantly emits, the so-called solar wind. Without that protection, the solar wind can rip off the atmosphere. That’s not good. Check out my earlier video about solar storms for more about how dangerous they can be.

That the solar wind rips off the atmosphere if the protection from the magnetic field fades away is what happened to Mars. Indeed, it’s still happening. In 2015, NASA’s MAVEN spacecraft measured the slow loss of atmosphere from Mars. They estimate it to be 100 grams per second. This constant loss is balanced by the evaporation of gas from the crust of Mars, so that the pressure has stabilized at a few milli-bar. The atmospheric pressure on the surface of earth is approximately one bar.

Therefore, before we try to create an atmosphere on Mars we first have to create a magnetic field because otherwise the atmosphere would just be wiped away again. How do you create a magnetic field for a planet? Well, physicists have understood magnetic fields two centuries ago and it’s really straight-forward.

In a paper that was just published in April in the International Journal of Astrobiology, two physicists explain that all you have to do put a superconducting wire around Mars, simple enough, isn’t it? The circle would have to have a radius of about 3400 kilometers but the diameter of the collected wires only needs to be about five centimeters. Well, okay, you need an insulation and a refrigeration system to keep it superconducting. And you need a power station to generate a current. But other than that, no fancy technology required.

That superconducting wire would have a weight of about one million tons which is only about 100 times the total weight of the Eiffel tower. The researchers propose to make it of bismuth strontium calcium copper oxide (BSCCO). Where do you get so much bismuth from? Asteroid Mining. Piece of cake.

Meanwhile on Earth. Will Cutbill from the UK earned an entry into the Guinness Book of World Records by stapling 5 M and Ms on top of each other.

Back to Mars. With the magnetic field in place, we can move to step 2 of terraforming Mars, creating an atmosphere. This can be done by releasing the remaining carbon dioxide that’s stored in frozen caps on the poles and in the rocks. In 2018, a group of American researchers published a paper in Nature in which they estimate that using the most wildly optimistic assumptions this would get us to about twenty percent of the atmospheric pressure on earth.

Leaving aside that no one knows how to release the gas, if we would release the gas this would lead to a moderate greenhouse effect. It would increase the average temperature on Mars by about 10 Kelvin to a balmy minus 50 Celsius. That still seems a little chilly, but I hear that fusion power is almost there, so I guess we can heat with that.

Meanwhile on Earth. Visitors of London can now enjoy a new tourist attraction, it’s a man-built hill of 30 meters height from which you have a great view on… construction areas.

Back to Mars. Okay, so we have a magnetic field and created some kind of atmosphere by releasing carbon-dioxide with the added benefit of increasing the average temperature by a few degrees. The remaining problem is that we can’t breathe carbon-dioxide. I mean, we can, but not for very long. So step 3 of terraforming Mars is converting carbon-dioxide to di-oxide. Only thing we need to do for this is to grow a sufficient amount of plants.

There’s the issue that plants tend to not flourish at minus fifty degrees, but that’s easy to fix with a little genetic engineering. Plants as we know them also need a range of nutrients they normally get from soil, most importantly Nitrogen, Phosphorus and Potassium. Luckily, those are present on Mars. The bigger problem may be that the soil on mars is too thin and too hard which makes it difficult for plants to grow roots. It also retains water very poorly, so you have to water the plants very often. How do you water plants at -50 degrees? Good question!

Meanwhile on Earth you can buy fake Mars soil and try your luck growing plants on it yourself!

Ok, so I admit that the last bit with the plants was a tiny bit sketchy. But there might be a better way to do it. In July 2019 researchers from JPL, Harvard and Edinburgh University published a paper in Nature in which they proposed to cover patches of Mars with a thin layer of aerogel.

An aerogel is a synthetic material which contains a lot of gas. It is super light and has an extremely low thermal conductivity, which means it could keep the surface of Mars warm. The gel would be transparent to visible light but can be somewhat opaque in the infrared, so this could create an enhanced greenhouse effect directly on the surface. That would heat up the surface, which would release more carbon dioxide. The carbon dioxide would accumulates under the gel, and then plants should be able to grow in that space. So, we’re not talking about oaks but more like algae or something that covers the ground.

In their paper, the researchers estimate that a layer of about 3 centimeters aerogel could raise the surface temperature of Mars by about 45 Kelvin. With that the average temperature on Mars would still be below the freezing point of water, but in some places it might rise above it. Sounds great! Except that the atmospheric pressure is so low that the liquid water would start boiling as soon as it melts.

So as you see our move to Mars is well on the way, better pack your bags, see you there!

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