Could Humans live on Mars?

This is a good question because if we intend to explore Mars we're going to have to live there for an extended time period. Even more important would be for us to colonize Mars.

First of all, we have to get there, and that means a long spacecraft ride, but that's for another post. Currently, it would take months. Right now, I'm concerned about the possibility of living on Mars.

Mars is about one half the size of Earth and has 0.107 times the mass of Earth, so it has less gravity than Earth, about 0.376 times. The temperature on Mars varies from -143 C to 35 C with an a mean temperature of -63 C. That's cold. The atmosphere is much less than Earth's, about what would be like 22 miles above the surface of Earth. Most of the atmosphere is composed of carbon dioxide, with only traces of oxygen and water vapor. So, a human must wear a pressure suit and carry oxygen to breath, and some means to provide warmth.

But, that's not the only problem. Since Mars has very little in the way of a global magnetic field, anyone walking on the surface would be bombarded with cosmic rays and the solar wind from the Sun. One could survive normal amounts of radiation, but a solar flare or coronal mass ejection aimed at Mars would kill a human.

The good news is that there is water on Mars, at the poles and probably under the surface. Water could be separated into hydrogen and oxygen by electrolysis. So, if one brings a nuclear power generator, one could subsist on the water and electrolysis produced oxygen indefinitely.

But, what about food? Theoretically, one could grow food on Mars if the soil would support it. If nothing more, one could employ hydroponics as long as the pressure and temperature of the artificial atmosphere was enough to support liquid water. Martian soil contains magnesium, sodium, potassium and chlorine. These nutrients could mean that crops could be grown in Martian soil. However, there is evidence to indicate that the regolith on the surface contains perchlorate chemicals. These would kill any organic based life, except for some bacteria that uses it as an energy source.

Mars often has dust storms and dust that contains perchlorates could jeopardize an astronaut's space suit. Perchlorates could cause corrosion of the suit materials. Perchlorates are oxidizing agents.

Most Mars colonization scenes in movies or stories show habitats on Mar's surface. Actually, the best place to live would be underground. Since Mars was once geologically active (volcanoes) there are sure to be lava tube caverns under the surface. We now know that these lava tube tunnels exist on the moon, and they should also exist on Mars. Living in a cavern under the surface provides natural protection from radiation and it also allows for some degree of temperature stability. Closing off a cavern with an airlock would make it possible to create an artificial atmosphere inside. Mining operations could still be done and exploration of the surface under favorable conditions (during the day and in the summer seasons) could be continued. The other advantage of living underground is to avoid asteroid collisions. Since Mars has very little atmosphere, most small asteroids strike the surface. These objects would be burned up in Earth's atmosphere. There is one other advantage of living underground. Mars has frequent dust storms that would be dangerous for anyone on the surface.

The Southern Hemisphere of Mars would be the best place to live. This part of the planet does have a weak magnetic field left over from the original global field. This has been deduced because of the observations of aurora there.

The bottom line is that humans could survive and live on Mars. When this will happen is anyone's guess.

Thanks for reading.