Mars is cold and brutal. But it’s our closest neighbor and if we’re to become a true spacefaring species, traveling to Mars and eventually living there is critical to our survival in the universe.
In order to put people there to live long-term without having to be cooped up in special air-tight buildings, terraforming Mars to be more hospitable to human life. It doesn’t have to become a tropical paradise, just livable.
So how can we do that, and how long will it take? Is it even possible?
Terraforming Mars
Terraforming Mars would center around a few basic things that humans need to survive which Mars currently doesn’t provide. Each of these items must be addressed before humans could consider living on Mars without special shelters.
1. Atmospheric Composition
The Martian atmosphere is mostly carbon dioxide. Humans cannot live in such an environment without special breathing equipment.
In order for humans to be able to breathe unassisted in the Martian outdoors would require an oxygen-rich atmosphere. So how can we get that?
The easiest way to increase the oxygen on Mars would be to grow plants there. Plants require carbon dioxide to grow and in that process, they release oxygen. This process may actually be how Earth got much of its oxygen we breathe today.
One challenge would be growing plants in alien soil. It’s widely thought that at least some earthly plants could take root in Martian soil. We wouldn’t expect any plants to grow on Mars as well as they do in their native habitat on Earth, but they really just need to survive long enough to contribute to the oxygen content of the atmosphere and create enough organic material as they decompose to provide richer soil for additional plants.
Another challenge to growing plants on Mars is the sunlight. Mars is a lot further from the sun and so the photosynthetic processes most plans rely on to grow won’t work so well. Perhaps with some genetic manipulation or using plants already adapted to grow in low light, there may be some potential.
Finally another great challenge to growing plants on Mars would be providing adequate water for the plants to grow. While Mars likely has plenty of ice, humans won’t be there to melt it and tend to the fields. Any plants being grown would likely have to be kept in some type of greenhouse.
2. Atmospheric Pressure
One of the most damning problems with terraforming Mars has to do with the pressure of the atmosphere itself. The Martian atmosphere is incredibly thin, about 1% that of Earth.
According to a 2018 study, it’s essentially impossible to increase the Martian atmospheric pressure to something humans could survive using current-day technology. This is due to the fact that even if all of the CO2 and water vapor contained in the Martian ice caps and soil could be vaporized and put into the atmosphere, it still wouldn’t be enough to support human life. To put it simply, Mars itself just doesn’t have enough raw materials to thicken the atmosphere enough.
Well, that’s awfully depressing. But, remember we’re still talking about present-day technology. Creating technology that could carry the raw materials to Mars is still a possibility, even if lies in the far future.
3. Temperature
There’s an obvious importance to a livable temperature. Without it, you have to spend energy to melt ice into liquid water and create warmth so humans don’t freeze to death on the planet’s surface. The easy part though is if you can take care of the first 2 items we’ve talked about, then temperature might just take care of itself.
A thicker atmosphere with plenty of oxygen, carbon dioxide, & water vapor would cause a greenhouse effect that could warm the planet. It doesn’t have to be toasty, just enough so that humans can survive.
So How Long?
It’s really hard to say. But we might be able to start terraforming Mars in the next couple of hundred years if we don’t destroy ourselves first. It will all depend on us developing the needed technology to do so and it would still require a lot of luck. Unfortunately, it means none of us will be alive to see it happen because even if we begin terraforming Mars sooner, the process may take hundreds or thousands of years.
But there is some consolation. It is likely we’ll see humans on Mars in the next 30-50 years. With high tech pushes for a manned mission to Mars by private companies like Space X, these will help pave the way for human colonization on the red planet.
That colonization will probably be limited to living either under ground or in pressurized domes with life support systems – which isn’t as sexy as terraforming. But hey you’ve got to start somewhere right?
Having a long-term presence on Mars will give mankind the ability to do more research on the planet and come up with better ideas for terraforming the environment.
Problem #1: Not enough gravity to hold a significant atmosphere.
No fix for that.
Problem #2: Almost no magnetic field. So can’t deflect high energy solar particles that reduce atmosphere and sterilize the surface.
No fix for that.
Solution 1: Bore a tunnel into side of crater from inside the crater halfway up from bottom, foam seal the tunnel and put tight firm end on it to hold atmosphere. The thickness of the soil above will stabilize the shape of the tunnel and/or underground “dome” made at end of tunnel.
Solution 2. Build dome on surface to grow plants. Only needs to be strong enough to survive sand storms and hold enough heat and light to keep plants alive. Oxygen the plants discard can be used in tunnel below.
I believe you’ve described one of the most likely scenarios. Underground dwelling would likely be more efficient and effective than surface dwelling. I suppose in time, pressurized buildings could be built on the surface once a permanent human presence is there.
The largest challenge, by far and away, in terraforming Mars is the need to transport an atmosphere and oceans worth of mass, possibly from the likes of Titan, …it no longer appears to be the case that one could simply use super greenhouse gases to cause a runaway greenhouse effect and do most of the work, ..as there is simply insufficient native water or gases on the planet.
That being the case,… it really begs the question, ‘Why not Terraform Venus?’, as it actually has a surface gravity comparable to Earths,.. so you don’t risk subsequent generations of weaklings, …and the fact that we’d have needed to master interplanetary logistics at such a massive scale in the first place, means it wouldn’t really be any more difficult to terraform(at least properly) Venus than Mars.
I assume the primary problem with Venus would be it’s current runaway greenhouse effect. There’s little in the way of ideas on how to fix that. Taking water there means nothing if it just evaporates away instantly.