Written by: Matt - a NSE team member
Terraforming quite literally means “Earth-Shaping”.
This involves changing a planet, moon, or any other celestial body by modifying its atmosphere, temperature, surface topography, or ecology to be similar to Earths environment and make it habitable by Earth life. An important note is terraforming a planet is very different than just using technology to live on a planet. Take the popular movie, The Martian for example. Matt Damon is able to survive for months on Mars by living inside their base, their Martian land rover, and wearing a spacesuit. The true terraforming of Mars would be Matt Damon being able to grow his crops outside of the base and without the protection of his spacesuit.
The concept of terraforming was developed from science fiction and bled into real science. Although the concept itself has been around for a long time, the term is credited to be first coined by Jack Williamson in his science-fiction story Collision Orbit published in 1942.The feasibility of altering a planet or other type of celestial body to a point where it is habitable, has yet to be established.
Mars is usually the first body to come to mind when considering the most likely candidates for terraforming. So why can’t we live on Mars now? What are the differences in the two planets' atmospheres preventing us from living and breathing? First, the Martian atmosphere is extremely thin, (about 1% of Earth’s atmosphere). It is also toxic to humans (made of CO2) and extremely cold (-60°C or very, very cold°F) due to both its thin atmosphere and distance from the sun. Finally, Mars only has 1/3 the gravity as earth and does not have a magnetosphere meaning we would have no protection from the suns radiation.
A ton of studies have been done concerning the possibility of heating the Martian planet and altering its atmosphere, NASA has even hosted debates on the very topic. The first thing we would need would be a “Greenhouse Effect”. Greenhouse gases are responsible for warming the temperature of the Earth. If we have any shot of surviving on Mars, we would need them there as well. The primary greenhouse gases in Earth’s atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. If Earth did not have these greenhouse gases, it is estimated that the average temperature would be around 15°C, so their importance to us is obvious. Methane can be obtained from mining rocks already on Mars, but more importantly, we will need Nitrogen. There are many theories that say smashing ice comets from the outer solar system into the Martian atmosphere would release Ammonia. Ammonia (NH3) is mostly Nitrogen by weight so, once Oxygen is introduced through plant life, theoretically, we could have an atmosphere quite similar to Earths.
Of course, you cannot write an article about Mars without talking about Elon Musk. He recently doubled down on a tweet he made about four years ago with an idea to “Nuke Mars”. Although it sounds crazy (as most of his ideas do), there is a point to be made. His plan is to nuke the polar ice caps of Mars. This would do a few things to help put Mars a few years ahead of itself when it comes to terraforming. First, it would release a ton of those greenhouse gasses we talked about helping to substantially increase the temperature of the red planet. Melting the polar ice caps also has potential to create surface level water! As crazy as Elon Musk sounds with this idea, he usually ends up proving everyone wrong at some point or another, so I’m not taking this out of the picture either.
All of these ideas to help the atmosphere are great, but a bigger problem is still the magnetosphere. Without it, any atmosphere created will be washed away by solar wind. So, why not Venus? It has a similar mass to Earth, similar density, similar gravity, and would also take about 4 months less to travel too than it would take to get to Mars. On top of all of that, it has an extremely thick atmosphere, so thick, that it would be too hot to live on. With that being said, 30 miles up from the surface, is an atmosphere much more similar to Earth’s. There have been concepts of creating flying colonies in the upper atmosphere of Venus. But living in the upper atmosphere of another planet doesn't spark the imagination quite as much. Humans want to step foot on another planet. And if society isn’t excited about it, there’s no chance of getting any funding.
The object with an atmosphere most like Earths on the surface is Titan, the largest moon of Saturn. We are just sending our first aerial drone to study the surface of Titan further, so unfortunately it will be a very long time before we consider trying to get humans out there.
Many of the methods that we talked about above could potentially work and fall within the current technological capabilities of humanity today, but the economic cost of any of these projects are way beyond what any government is willing to put into it (cue SpaceX and the private sector!). And we didn’t even talk about any of the ethics of terraforming and if we even should attempt to change a celestial body to make it livable for humans.
Leave a comment below on your terraforming thoughts!