Can Humans Live on Mars?
For now only robots have lived on Mars. But, what about future colonists?
We now know that Mars can be very cold, very dry, and very inhospitable. Nevertheless in their current form, Mars and Earth actually have a lot in common:
- The Martian day (or sol) is 24 hours 39 minutes and 35.244 seconds.
- Even though Mars is very cold, temperature can get as high as 35 °C (95 °F) during summer and midday at the equator.
- The red planet has an axial tilt of 25.19° (Earth: 23.44°) resulting in 4 seasons.
- Mars has 144.8 million km of land mass. (97% of Earth)
- Gravity of Mars is: 3.711 m/s² (38% of Earth) and is far better than Moon´s gravity for us: 1.62m/s².
- Recent observations by NASA have confirmed the presence of water ice on Mars.
- Mars also has polar ice caps (water ice and CO2 ice)
When referring to exoplanets, the term “habitability” is usually equated to a hospitable combination of factors: right amount of temperature, atmospheric pressure, level of oxygen, liquid water, and biomass. Also scientists look for planets that are inside the Goldilocks Zone (habitable zone) where the temperature is just right for liquid water to exist and maintain. But all this doesn´t always answer the question of whether humans can inhabit a given environment. After all, low-Earth orbit (ISS) doesn´t meet all these requirements, yet resourceful humans have been inhabiting this location for almost 2 decades.
So, what about Mars? Mars is on the outer boundary of our solar system’s habitable zone, and liquid water can exist on the surface for very short periods of time. But does that really make Mars a habitable planet? The answer depends on what technologies we bring there to create our own bubble, an artificial habitat.
Living a long period on Mars will require us to know how to use Martian raw materials for our survival. Fortunately, Mars has a wealth of materials needed to support human life (carbon, nitrogen, hydrogen, and oxygen). All this, make the red planet the most human-habitable place in the solar system, other than the Earth.
Although most scientists think we could live long periods of time in Mars sustainably, humans can´t live there freely and without suits/habitations without dying almost instantaneously. The solution to that (very slow and difficult) is terraforming. For terraforming a planet, you have to modify some things first:
- Temperature: The first step toward habitability is achieving a stable, survivable temperature (average of 14°C). The best idea right now is to use orbital mirrors to reflect sunlight onto Mars and heat the surface, releasing greenhouse gasses.
- Pressure: This is the most important factor of a planet’s atmosphere (100,000 pascals at sea level). We could increase Mars pressure (thicken atmosphere) with large greenhouse gas factories, a much difficult option is to release gases from pockets locked deep beneath the surface.
- Oxygen: For human life to survive you need the right amount of air to be breathable O2 (18–24%). Scientists have developed a solar-powered machine that extracts pure oxygen from carbon dioxide found in the thin Martian atmosphere.
- Water: One of the most famous keys to life as we know it is water. With the rising temperature in the planet, buried ice will melt and seep up from underground. Earth-like blue skies could appear, and rivers and oceans could return.
- Biomass: Humans will need to start seeding plant life and building a global ecosystem. Scientists will have to introduce ammonia-producing microbes into the Martian soil that will convert nitrogen from the atmosphere into the soil for larger plants like grasses and mosses to grow.
Now that we have hypothesized about living and terraforming Mars, the question is: Why would we want to move to Mars?
First of all, moving to Mars doesn´t mean we don’t have to take care of Earth. We can explore new planets, exceeding our limits, without leaving our first home behind. Going to Mars is about progress; progress of science, humanity, culture, of our entire civilization.
“You want to wake up in the morning and think the future is going to be great — and that’s what being a spacefaring civilization is all about. It’s about believing in the future and thinking that the future will be better than the past. And I can’t think of anything more exciting than going out there and being among the stars.” — Elon Musk
Originally posted on old elonsworld.space blog