No, we will not be occupying Mars

I know it’s disappointing, but you can drop this idea

First, there is too much radiation. Radiation from the sun and radiation from across the galaxy is enough to fry any Mars colonists who were to live there for more than a short while. Sure, heavy duty spacesuits and heavily shielded living structures could stave off the radiation onslaught for a while, but it wouldn’t be enough for a long term stay on Mars.

And the radiation problem on Mars is not fixable. One of the reasons that we don’t get fried by radiation here on earth is that the earth has a wonderful magnetic field. That magnetic field is what causes the Aurora Borealis that everyone likes so much. We can literally see the damaging radiation being dissipated by the earth’s magnetic field. That magnetic field is created by the earth’s molten iron-nickel core flowing around the solid iron center of the planet. The amount of energy created by this effect is approximately a gazillion times larger than the total amount of energy ever produced by humanity in all of history. Mars is magnetically dead, and there is no way to melt the iron that does exist in Mars’ core to ever get it to flow so that it could generate a magnetic field.

Besides the lack of a magnetic field, the lack of an atmosphere also contributes to the radiation problem. Pop culture represents Mars as having a thin but manageable atmosphere, but that isn’t accurate. Mars has only 1% of the surface atmospheric pressure of the earth. This makes it much more like the surface of the moon, which has no atmosphere, than what we see in movies about Mars. There is essentially no atmosphere to help shield out harmful solar radiation.

The second big problem is the low gravity on Mars. The planet has about half the diameter of earth and only about 10% of earth’s mass. This generates gravity on the Martian surface that is a little more than a third of the gravity that exits on earth. Like the radiation problem, the low gravity problem is not fixable. There is no way to increase the mass of Mars so that it would generate gravity that is close to earth’s. Human colonists living on Mars would eventually suffer from muscle atrophy, bone density issues, and problems with organ function and heart health due to the low gravity. When astronauts go on long missions to space these problems always occur. Special exercises in zero gravity help to stave off the effects, but they can’t completely prevent them. A colonist living on Mars permanently would die from effects of low gravity, no matter what was done to mitigate the effects.

Humans are adapted to living on earth, and despite science fiction movies, there’s no way for us to travel to the stars, or even to planets in our own relative backyard. It might be disappointing, but we are stuck on earth permanently. It’s actually not that bad: If we’re going to be stranded, earth is a really nice planet to be on.

Though it’s impossible to have a human colony on Mars, we can, and should, send more mechanical research probes to Mars. Early in its history, maybe 3 billion years ago, Mars may have had both a global magnetic field and an atmosphere. These could have made conditions right for the existence of liquid water on the surface of the planet. Research probes could help us uncover the ancient history of Mars and find out if there was life on the planet at one time. This knowledge would be important to our understanding of life on earth. If we had any sense, we’d ditch the idea of sending people to Mars and instead send enough mechanized probes to explore every inch of the planet.