In grand science-fiction fantasies, we imagine a universe dotted with planets that are perfectly capable of supporting human life. We have a vast assortment of planets from which to choose, and humans hop and skip from one hospitable globe to another, depending on their preferences.
This will be a reality some day. Right?
In the near future (and by “near” we mean hundreds of years from now), humans may live in cocooned settlements on the Moon or Mars. But eventually, we will need to be able to step out and walk around, all without equipment or survival gear.
This means we need to create atmospheres. This means we need “terraforming.”
But could it be possible, or is terraforming simply the fantasy of imaginative science-fiction writers?
Right now, we are just beginning to grasp the possible options and starting to wrestle with the colossal challenges presented by terraforming. And as we’ll learn, we are still a long ways from even coming close to terraforming a planet.
1. Terraforming 101: Transforming an Inhospitable Planet into An Human-Friendly Oasis
First, we need to understand what terraforming is and what it is not. Terraforming is the process of changing a planet or celestial body’s atmosphere so that is can sustain life, particularly human life.
The concept would seem like a rather modern theory, but it actually dates back decades. The first use of the term is credited to science-fiction writer Jack Williamson, whose 1942 story “Collision Orbit” featured the concept. But the concept of changing a planet goes back further, even if the term “terraforming” was not used.
Since the mid-20th century, the concept of changing a planet’s atmosphere has captured our imagination, appearing in numerous works of fiction, including movies, books, and even video games.
One of the main components of terraforming is creating a source of oxygen. However, to make a planet hospitable for humans, we need more than just breathable air. Among the many other factors, we also need a shield from the sun’s dangerous radiation. On Earth, we have a nice magnetic field that blocks the sun’s radiation, keeping us healthy and happy. On Mars, the Moon, and other areas of space, we don’t have that luxury. So not only do we need to create a source of oxygen, we also need to find a way to block the sun’s radiation.
These are just two of the staggering challenges that come from terraforming.
Where to Terraform?
First, it helps to look at where we could possibly terraform. After all, terraforming one place, such as the Moon, would be completely different than terraforming another, such as Mars.
1.1 The Moon: Close Proximity, Not Enough to Work With
The Moon presents a tempting location for experimentation in this process. Because it is so close, it would be relatively easy to ship supplies to and from the moon, so it seems like an obvious first choice. However, the basic elements that are needed to support life, such as hydrogen, nitrogen, and carbon, are not found in large quantities on the Moon, so while we can reach it, we would need to somehow inject the Moon with the appropriate elements. It sounds simple, but that would be a staggering task.
1.2 Mars: The Popular Choice for Terraforming
Currently, Mars is the best conceivable option for terraforming. It’s close enough to access, (we’ve already landed our technology on Mars, just not ourselves) and has the basic building blocks to potentially become a habitable planet. But as we’ll learn, utilizing these resources is neither simple nor easy.
Mars is surprisingly similar to Earth in many ways. It once had an atmosphere, so there is the chance that it could have an atmosphere again. Also, it once had warm, flowing water, and we know there is frozen water on the planet. With the basic building blocks in place (probably), Mars is far and away the popular choice for the first terraforming efforts.
1.3 Are There Other Options in Our Solar System?
In addition to Mars, are other planets that have been considered as potential candidates for terraforming. One option, which was proposed by famous scientist Carl Sagan, is Venus. In the 1960’s, it appeared that Venus had the right stuff for terraforming, but the discovery of clouds made from sulfuric acid, as well as Venus’s crushing atmosphere, make even visiting this planet an extreme challenge.
The other potential candidate is Mercury, but like Venus, the conditions make it virtually impossible. Temperatures can reach over 400 degrees Celsius, with extreme cold at the poles. Besides that, the distance to Mercury makes it extremely difficult to reach. We’d like to start a little closer to home.
1.4 What About Exoplanets?
The other option for terraforming could be exoplanets, which are planets outside of our solar system. However, reaching these exterior bodies is, for now, not even in the realm of feasibility, and likely won’t be for thousands of years, if ever.
So for now, we’ll stick with our solar neighborhood, which means turning our attention to the Red Planet. This is the planet that has most been studied in regards to terraforming, so it gives us the best look at how this process might be possible.
2. What are the Options for Terraforming Mars?
To help understand the options for terraforming, we’re going to narrow our focus specifically on Mars. Terraforming other locations, such as the Moon or Venus, would take a different path, so for simplicity we will stick to this specific location.
2.1 CO2: The Key to Terraforming Mars (as we currently understand it)
Mars has no greenhouse effect, a process that keep Earth warm by trapping the sun’s rays. Because there is no atmosphere to warm the planet, the first basic step to warming it and creating conditions for life would be to create an atmosphere, which would mean releasing any available CO2.
Because Mars once had an atmosphere, you might assume all that is needed to terraform the planet would be to release the atmospheric gases and elements. But this atmosphere didn’t simply seep into the surface or turn from gas into solids. Instead, the scientific community is fairly certain that the atmosphere was swept away into the cosmos by solar winds. So instead of rejuvenating a dormant atmosphere, we need to create a new one, potentially by releasing a supply of CO2 buried deep within the surface.
Release C02 in the Martian South Pole?
Scientist believe that there is a rich deposit of CO2 buried in the south polar ice caps. It’s been theorized, therefore, that if all the CO2 in the south pole were released, it could possibly double the amount of CO2 in the atmosphere. This has led some to speculate that simply sending a nuclear bomb to Mars’ south pole would release those gases, create a greenhouse effect, and thereby create an atmosphere. This, however, would still be far too low to make a difference. By simply doubling the amount of CO2 in Mars’ atmosphere, we are still low compared to the Earth’s; we would still need about 100-times more CO2!
Another source of CO2 is actually the dust sitting on Mars. Dust on the planet holds CO2, and this could be found up to 100 meter deep, creating a large and accessible source for the gas. If this dust were to somehow be heated, it might release its CO2 and create an atmosphere. But again, we would fall short, only getting about 4% of the Earth’s atmosphere.
Carbonate Minerals in Mars’ Crust
A third potential source is carbonate minerals located in Mars’ crust, near the surface. If extracted, processed, and properly heated, these carbonate minerals could release CO2, but once again we would fall well short of the total supply needed for creating an atmosphere on Mars.
Carbonate Minerals Deep Beneath the Surface
The only source of enough CO2 (that we currently know of) is carbonate minerals buried deep beneath Mars’ surface. These minerals are likely the only source of enough CO2 to make a difference, but accessing and processing them would be even more difficult than the previous three options.
2.2 Dealing with Radiation: The Neglected Task of Terraforming
Let’s say that we are somehow able to terraform Mars. Bully for us…until the sun sweeps our cozy atmosphere away. Earlier, we discussed the well-established fact that Mars previously had an atmosphere, but the atmosphere was slowly shaved away by solar winds. There is nothing to stop that from happening all over again, so we would need to create a shield for our nice little home.
Earth is protected thanks to a large magnetic field, but Mars has no protective shield. To give it one like Earth’s, we would have to melt the entire core, which would take an impossible amount of energy. A better option, although still far from our current reach, would be to place a field generator between Mars and the Sun to act like a magnetic umbrella.
2.3 Paraterraforming: The Most Likely First Option
Getting the right equipment to Mars, then utilizing and trapping CO2 in order to kickstart a new atmosphere is, by all accounts, extremely difficult. The options that are conceivable wouldn’t yield enough CO2 to make a difference, and the technology needed to access deeply-buried minerals is not within our grasp. Then we would need to create some sort of shield from the sun’s radiation.
It seems that instead of terraforming an entire planet, we should focus on “paraterraforming.”
Paraterraforming is the process of creating smaller bubble-like habitations, called “worldhouses,” that provide a safe shelter from the elements. Instead of making Mars, the Moon, or Venus habitable, we would instead create an encapsulated shelter that holds it’s own life-sustaining atmosphere.
There are many concepts about how this would work, but essentially it would be a transparent roof that would be suspended about a kilometer above the surface. The area would be pressurized to simulate the same pressure as the Earth, and it would have a breathable atmosphere, allowing people to walk around without the need for breathing suits or other equipment.
The approach seems far more feasible, at least with the technology we have available at the current time. It would allow humans to slowly populate a planet, and allow us to live off of the Earth much sooner.
Many of the same challenges persist with paraterraforming as with terraforming. There is still a need to protect from radiation, and you would need a source of CO2 and other elements to create an atmosphere. However, it’s possible that building materials could be created to give protection from radiation, and the amount of elements needed would be far smaller; because the overall space being “terraformed” is smaller, the CO2 in surface dust may be enough.
The house would, however, need to be extremely strong, as meteorites and other space debris, which are burned in the Earth’s thick atmosphere, would have an easy path to a worldhouse on Mars.
3. If Terraforming is Possible, When Will It Happen?
Okay, now down to the most important question: when will terraforming actually happen? While some of young people reading this article may get to see small-form paraterraforming in their lifetimes, it seems that real terraforming is not going to happen any time in the next century; it may in fact be 1,000 years or more until this is actually a reality.
For some time, the general consensus was that terraforming, while difficult, could be possible in the near future. But NASA dropped a press release that shattered the hopes of many terraforming dreamers. According to the 2018 press release, “transforming the inhospitable Martian environment into a place astronauts could explore without life support is not possible without technology well beyond today’s capabilities.”
The NASA press release triggered a trend of articles that read like obituaries for the concept of terraforming Mars. But it’s important to note that NASA did not say it was impossible; they said it was impossible with today’s technology. (There is a big difference!) Unfortunately, the press release gave little information on when we might have that technology. The article simply concluded that terraforming Mars would be “very far into the future.”
4. Final Conclusion: Terraforming is REALLY Hard
In many works of science fiction, terraforming is presented as a simple, straightforward process. Heat a few rocks here, release oxygen there, blow up a nuclear bomb or two, and you have a livable, comfortable planet.
But as we’ve learned, the process is not so simple. Terraforming requires a vast amount of resources, a staggering amount of energy, and innovations that we have not yet been conceived.
But that doesn’t mean we should stop thinking about it. First we will develop paraterraforming and, most likely, using what we learn from that process, we may eventually turn Mars, the Moon, Venus, or even Mercury into a thriving human colony.