Terraforming Mars

Podcast Transcript

Ever since the dawn of the space age, there have been some who have dreamed of establishing a human presence on Mars.

However, in addition to being really far away, Mars is not exactly hospitable to humans.

Some suggest that the answer might be to completely change Mars’s environment, to radically change its atmosphere, and, over time, to turn it into a second Earth where humans could live.

Learn more about the idea of terraforming Mars, what would need to be done, and the challenges it would face in this episode of Everything Everywhere Daily.

The idea of terraforming a planet is a relatively new one.

Terraforming is defined as “the process of deliberately modifying the atmosphere, temperature, surface topography, and ecology of a planet, moon, or other celestial body to make it more Earth-like and suitable for human habitation.”

As of right now, and probably for the foreseeable future, this is a totally hypothetical process that has been in the realm of theorists and science fiction writers.

Astronomer Carl Sagan first seriously considered the idea, writing a paper in 1961 about terraforming the planet Venus.

The idea of terraforming Venus is as interesting as that of terraforming Mars, but the problems are almost totally opposite of each other.

Venus’s surface is extremely hot, with a temperature of 467 °C or 872 °F. The atmospheric pressure on the surface is equivalent to the pressure found 900 m or 3,000 feet below the ocean’s surface. The atmosphere consists of 96.5% carbon dioxide and 3.5% nitrogen, and just to make things worse, it has clouds of sulfuric acids.

The surface conditions are so brutal that only four landers have ever been sent to the surface of Venus, which returned photos, and they only managed to send six images between the four of them because their lifespan on the surface was so short.

Mars, on the other hand, is at the other end of the spectrum. Its atmosphere is extremely thin, and its surface is very cold.

Sagan brought up the idea of Mars terraforming in 1973, which got more attention.

In 1976, NASA commissioned a study, which took place around the Viking landings on Mars, which concluded that the transformation of Mars into a habitable planet was theoretically possible.

Many space theorists and science fiction writers have kicked the idea around for several years. While there are many ideas that have been proposed for how to go about doing it, there is wide agreement on what the problems are.

I should note that many of these problems are intertwined. The process of solving one will help solve something else.

So, with that, the first problem preventing humans from living on Mars is the atmosphere.

For starters, the Martian atmosphere is extremely thin. Its surface pressure is less than 1% of Earth’s. This would make it impossible for liquid water to exist on the surface without freezing or sublimating.

It also means that any humans that visit Mars would have to wear pressurized space suits just as if they were on the moon or conducting a space walk.

What little atmosphere it does have isn’t fit for humans to breathe. The Martian atmosphere consists of 95% carbon dioxide, 2.85% nitrogen, and 2% argon. Less than 1% is oxygen, water vapor, and carbon monoxide.

So, how do you go about increasing the atmospheric pressure of an entire planet?

The most obvious solution would be to unlock the frozen carbon dioxide in Mars’ polar regions.

Mars’ Southern Polar Cap is the larger of the two polar caps and contains most of the frozen CO?. Estimates suggest that if all the CO? in the southern polar cap were released into the atmosphere, it could raise Mars’ atmospheric pressure to about 30 to 60 kilopascals. For comparison, Earth’s average surface pressure is around 101 kilopascals.

This obviously is a far cry from the pressure on the surface of the Earth. However, in some ways it is good enough. This would be in the ballpark of the pressure on the top of Mount Everest.

If the pressure of the Martian atmosphere could be raised to a point where it was a significant percent of the Earth’s, you wouldn’t need a pressure suit to walk on the surface. All you need is to breathe oxygen, which is not too dissimilar to what mountain climbers have to do on Everest.

So, how do you melt the polar caps? Here is where there are host of ideas and where the planetary engineering came in.

One would be to pump super greenhouse gases into the atmosphere. This could be ammonia, sulfur hexafluoride, chlorofluorocarbons, or perfluorocarbons. The problem is that all of these chemicals would have to, at least initially, be brought from Earth, which would be incredibly expensive.

One recent suggestion is to make nanorods out of aluminum or iron, which can be found in abundance on Mars. These tiny rods with a length of 1 to 100 nanometers could be suspended in the atmosphere and trap heat 1000x more effectively than other greenhouse gasses.

Another plan would be to put mirrors in orbit, which would focus light on the southern polar region.

Another proposed solution would just be to detonate nuclear weapons over the southern poles. It would be fast, and you wouldn’t have to worry about contaminating the environment because there is nothing in it.

There is another problem on Mars that increasing the pressure would help alleviate, and that is temperature.

Mars is cold. The average temperature on Mars is around -60°C or -80°F, with even colder extremes at the poles. This is due to the lack of atmosphere and the distance to the sun.

The act of melting the poles would, by whatever method, increase the amount of CO2 in the atmosphere which would help warm the planet. The more CO2, the warmer it would get.

Changing the atmosphere would have to be a part of any solution to change the temperature of the planet, but it isn’t the only thing. In fact, there probably isn’t enough CO2 on Mars to appreciably trigger a serious greenhouse effect.

One thing that could be done is to darken the surface of the planet. By reducing the planet’s albedo, that being the amount of light reflected by the surface, more heat could be absorbed.

How do you do that? One idea is to crush up one of the moons of Mars into dust and then spread it across the planet, or perhaps at least the poles. The darker surface would increase the amount of heat retained.

Another potential solution is to try to mimic what happened on Earth by using life. The idea here would be to bioengineer a type of algae or cyanobacteria that could survive in the martian atmosphere.

The algae would cover the surface, which could also reduce the planet’s albedo.

There is another thing that Mars lacks that is tied to the atmosphere. Surface water.

Mars is too cold, and the pressure is too low for surface water to exist for any extended period of time. There is some evidence that there might be liquid water on Mars that flows seasonally, and the water is probably very salty, which allows it to flow in cold temperatures.

So, at a minimum, if you want to have liquid water on Mars you need to raise the surface temperature to the freezing point of water. However, as you decrease the pressure of the atmosphere, it reduces the freezing point.

Even if you could increase the temperature of Mars, there probably isn’t enough water on the planet to have that much effect.

So, how do you get water to Mars?

You can’t very well take that much water from Earth. It would be a large percentage of the planet’s water, and the energy requirements would be enormous.

A far simpler idea would be to find water-rich comets in the solar system and send them crashing into Mars.

This is believed to be what happened very early on Earth, over 4 billion years ago.

It would probably take quite a few comets to be redirected to Mars, and it would take quite a while, but it would bring water to the planet…. A lot of it.

Smashing comets into Mars would also kick dust up into the atmosphere, which would cool the planet, which would counteract efforts to warm it.

If you could somehow get more water on Mars, it would also help solve the problem I brought up earlier: the composition of the atmosphere.

If you want to increase the percentage of oxygen, the extra water provides a source for it. You could use electrolysis to split the water into oxygen and hydrogen, or could seed plants to create it.

The interesting thing about all of the things I’ve just mentioned is that Mars probably did have a thicker atmosphere, a warmer climate, and liquid water a few billion years ago.

So, how did it lose its atmosphere?

Two things. The first of which is that Mars only has 38% of the Earth’s gravity. It is far easier for gasses to escape out into space with a weaker gravity.

However, the big difference between Earth and Mars is that Mars lacks a magnetic field.

The Earth’s magnetic field is what protects the planet from the Sun’s solar wind. The magnetic field deflects that charged particles that fly out of the sun, which would otherwise slowly strip the planet of its atmosphere.

That process is exactly what happened on Mars.

If Mars had a magnetic field, it only existed briefly. Once it was gone, the solar wind slowly stripped the planet of its atmosphere, a process that is still ongoing today.

The lack of a magnetic field would undo whatever you did to do to create a thicker atmosphere. If you melt the ice caps, you will eventually lose the CO2 into space. The lack of a magnetic field would also make radiation levels on the planet so high as to be dangerous.

Furthermore, as far as we know, there is no way to start up a planetary magnetic if it has stopped or if it never existed in the first place.

The lack of a magnetic field seems like an insurmountable obstacle to terraforming Mars.

However, there might just be a solution that would achieve the same thing.

It would involve a large electromagnet situated at Lagrange Point 1. This is a point in space where the gravity of Mars and the Sun are identical and it is a point directly between the Sun and Mars.

If you put an electromagnet there, it could deflect the solar wind around Mars. The magnet wouldn’t even have to be that powerful in the big scheme of things. A magnet of 1 Tesla might be sufficient…and the most powerful magnet in the world currently is 45 times more powerful.

Mars would be far enough away that it could effectually slipstream behind the magnet.

So, how realistic are any of the things I’ve discussed in this episode?

For starters, anything that was done would take centuries, if not thousands of years to complete. I’ve seen estimates as high as 10,000 years.

Needless to say, it is almost impossible to plan anything that far out. Most people and governments can’t really plan out further than their own life spans.

The biggest thing, however, would be the cost. It is unlikely that any government would ever attempt something like this. It would have to be a global undertaking, and most countries have more important things going on.

The estimated cost for terraforming Mars would run into the trillions of dollars, and the return on the investment would be had by generations that didn’t have to put up any money.

It would require a vast number of missions to supply Mars. Even something like Starship by SpaceX couldn’t supply the resources necessary for terraforming. It could probably only be done with the creation of a new type of space craft that hasn’t even been invented yet.

We really have no idea if any of this is even remotely possible yet as we have never come close to trying. So it is highly likely that we will never see this happen in our lifetimes.

So we had better take care of the planet we got, because we aren’t going to be getting a new one any time soon.