How We Can Terraform Mars
By: Leo Ferguson
Tags: Future, Space, Mars Colonization, Mars, Terraforming Mars

Methods to Terraform Mars

After identifying some similarities and differences between Earth and Mars it’s clear that the differences are substantial, and need to be addressed if humans will live on Mars for long periods of time. Essential things like gravity, the atmosphere, and temperature can only be worked around for so long. If humans are looking at Mars as a long-term investment it’s crucial to make the red planet more Earth-like. In addition, because the task of terraforming Mars is so difficult it requires a combination of strategies, all of which are quite complex.

Implementing a New Magnetic Field

Due to the smaller mass of Mars, its core cooled down about 4 billion years ago. Because of this, the magnetic field of Mars faded away, allowing for the atmosphere to be deteriorated by solar winds over millions of years. It would be incredibly difficult to give Mars a new magnetic field, so a common plan is to give it an artificial one. By placing a large magnetic dipole in Mars’s Lagrange point 1 it’s possible to simulate a magnetic field and deflect solar wind.

Diagram of Mars’s Lagrange points — Image Credit: Public Domain

A Lagrange point is essentially a point in space between two large objects, in this case the Sun and Mars, where the gravitational force cancels out and the smaller object in between is in equilibrium. This enables the magnetic dipole to follow Mars as it orbits the Sun, constantly deflecting solar wind that would destroy any significant atmosphere. This, on its own, would likely start a greenhouse effect on Mars. However, it would take millions of years to see any real progress in the development of an atmosphere.

Releasing Greenhouse Gases into the Atmosphere

On Earth climate change is certainly something to be addressed as more and more greenhouse gases are emitted into the atmosphere, trapping heat and thus warming the planet. However, on Mars it would be extremely beneficial to have such effects, as that would help to rebuild the faint Martian atmosphere and warm the planet up to more survivable temperatures. There are two ways this can be done in the near future;

Melting the Polar Ice Caps: The polar regions of Mars, particularly the southern one, has a lot of frozen water. Additionally, there are thick layers of carbon dioxide ice, more commonly known as dry ice. If the carbon dioxide from the polar ice caps is released it could certainly help to develop a more dense atmosphere, but even melting all the ice caps would still leave lots of progress to be made. Sending nuclear missiles on a collision course with the ice caps is a viable option but even that would not fully complete the job of releasing all the carbon dioxide.

One of Mars’s polar ice caps — Image Credit: European Space Agency

Heating the Martian Regolith: Martian regolith is essentially the soil on Mars. It’s significantly more fine and toxic than any soil on Earth. Carbon dioxide was absorbed into Mars’s regolith and through extreme heat can slowly be released back into the atmosphere. It would be extremely difficult to heat enough regolith to release any noteworthy amount of carbon dioxide. Scientists estimate that heating the surface of Mars for 10,000 years would result in an atmosphere only 4% as thick as Earth’s.

View of Mars from NASA’s Mars Exploration Rover Spirit — Image Credit: NASA/JPL/Cornell

These two plans for rebuilding the atmosphere of Mars are extremely complex, each requiring a large budget, the effort of many people, and the development and testing of new and complicated technologies. Unfortunately, it’s likely that both combined would get Mars’s atmosphere to only 5% that of Earth’s, not nearly enough if humans hope to stay. Even so, plans to implement these processes can be started in the near future. Listed below are two strategies that can be executed in the distant future to rapidly strengthen the Martian atmosphere;

Mining Carbonate Minerals: Another way to release carbon dioxide into the atmosphere of Mars is through mining for and subsequently heating up carbonate minerals such as calcite. The minerals would have to be heated up to a temperature of about 575 degrees Fahrenheit (300 Celsius). Even doing this across the surface of Mars wouldn’t generate that much carbon dioxide, most likely a similar amount to melting the polar ice caps. The machines mining for these minerals would have to be very advanced.

Depiction of astronauts mining carbonate minerals on Mars — Image Credit: NASA Langley Advanced Concepts Lab/Analytical Mechanics Associates

Redirecting Asteroids: If there was a fleet of spacecraft capable enough to redirect ammonia-rich asteroids to collide with Mars, that could rapidly speed up the terraforming process. Asteroids with ammonia can be found in the asteroid belt, which sits between Mars and Jupiter. When these asteroids collide with Mars the ammonia will be broken into nitrogen and hydrogen gas, helping to thicken the atmosphere and warm the planet. If the asteroids were big enough and plentiful enough this could be an efficient way to bring greenhouse gases to Mars, however it would take an extreme number of technologically advanced spacecraft that we don’t have the resources for as of now. Additionally, it’s possible to use spacecraft to transport carbon dioxide from the Earth, Venus, or Saturn’s moon Titan. Still, it would require mass amounts of a very advanced and efficient spacecraft, and that’s just not practical as of now.

Depiction of asteroids on a path to collide with Mars — Image Credit: NASA

Thickening Mars’s atmosphere through the release of greenhouse gases is not a task to be taken lightly, and will take at least a few decades, if not centuries to fully make it like the one we have on Earth.

Growing Plants and Moss

The next step to terraforming Mars is to start to grow specific types of plants and moss. Unfortunately, this also comes with its fair share of problems as Mars only receives about half the energy from the Sun as Earth does and a toxic chemical called perchlorate is found in much of the Martian soil. Luckily, there are some bacteria known to eat perchlorate, and with the help of filtering systems it’s possible to take much of it out of the soil. From there, plants and moss will be grown and spread across the surface of Mars, converting some of the carbon dioxide in the atmosphere to oxygen.

Depiction of a plant sprouting from the Martian surface — Image Credit: Samuel van der Hoeven

Because oxygen is lighter than carbon dioxide it will naturally drift towards the top of the atmosphere, where it will encounter ultraviolet rays from the Sun. When this occurs it will cause those oxygen molecules to split apart into two singular oxygen atoms, which in turn will combine with oxygen molecules of two atoms to make an oxygen molecule with three oxygen atoms, commonly known as ozone. Here on Earth our ozone layer is an essential part of the atmosphere. It keeps us safe by absorbing most of the Sun’s ultraviolet radiation. On Mars, it would do much the same thing, enabling humans to expose themselves to the natural sunlight without fear of absorbing too much radiation.

Afterwards, humans on Mars would just need to keep doing more of the same. It’s likely shipments of carbon dioxide would be needed every once in a while to sustain the greenhouse effect, and of course it would be crucial to look after the plants producing oxygen. At that point, the water from the polar ice caps that was not evaporated could form lakes and rivers. With plants producing enough oxygen it would then be suitable for humans to walk around on Mars, without a spacesuit, mask, or any other protective equipment. Mars would then truly be terraformed.

Creating Artificial Gravity

Because Mars has only 38% of Earth’s gravity, buildings with artificial gravity would need to be implemented in Martian colonies for astronauts to feel a normal level of gravity. This requires complicated buildings that use centrifugal force. While this is not necessary for immediate survival, it would be helpful. The effects of spending long periods of time on the Martian surface are not known, but scientists do know that astronauts on the International Space Station lose bone and muscle mass even with exercising for 1–2 hours a day. Therefore, it would likely be necessary for some sort of artificial gravity to be put on place if humans plan to inhabit Mars.