You asked:
Will any one ever live on the moon and/or Mars? — Zach, Baytown, Texas

Marshall Brain Answered:
To answer this question, we have to define what “live on” means.

When the Apollo astronauts landed on the moon and explored for several days, the “lived on” the moon. They lived there in the a “weekend camping trip” or “short scientific expedition” kind of way. But they did live there. Will that happen again? Absolutely on the moon. Almost certainly on Mars. If not the United States then some other country or coalition of countries will land again on both the moon and Mars. If for no other reason, it will be driven by human ego and the natural human urge to explore and try new things.

But that probably is not what you had in mind. There are several other ways to define “live on”:
1) Will human beings ever “live” on the moon or Mars for a period of a six months or more?
2) Will a continuously staffed colony ever exist on the moon or Mars, in the same way that we currently have a continuously staffed presence on the space station?
3) Will a group of people ever live in a self-sustainable way on the moon or Mars, giving birth to children who then give birth to more children so that the moon and Mars have their own natural inhabitants, with a growing population?

The idea of a six-month mission to Mars is natural because of the way that the orbits of Earth and Mars overlap. If we ever do make it to Mars, a six-month (or more) expedition is a natural thing. It seems likely that this will happen.

The idea of a continuously staffed scientific station on the moon that emulates the space station (or the scientific station in Antarctica) seems highly likely. If humans make it to the moon, it seems obvious that they would establish a “station” there. Whether or not this happens on Mars is much harder to determine. The cost of going to Mars is so high that it seems less likely. But an international coalition might be able to pull it off as they have with the space station.

Whether or not there could ever be a self-sustaining “colony” of humans on the moon or Mars is impossible to know right now because there are several holes in our knowledge. We do not know if human children can grow in less-than-earth gravity. We do not know about the long term effects of cosmic radiation, and whether we can effectively shield against it over long periods of time. We do not know if we can create a self-sustaining and expandable biosphere off-planet because it has never been tried before.

Then there is the whole idea of “terraforming”. See How Terraforming Mars Will Work for details.

See also: