[elihu]

Mars is a more hospitable, Earth-like environment for humans. It has an atmosphere, a normal-length day-night cycle, less extremes of temperature, and closer to normal gravity.

Mars and the moon both have pros and cons. Mars would be an easier place to survive, but the moon is easier to get to.

[ClumsyPilot]

The habitability difference is not relevant at this stage - both will kill you instantly. The ISS orbit has no atmosphere or gravity, but it's easier to keep people alive there than on Mars.

For a Moon base locations, look up peaks of eternal sunlight. We also have space-grade nuclear reactors and RTGs ready to go.

On the Moon you can have realtime communication, bring way more equipment, have robots remotely controlled from Earth, and get help or evacuate quickly. NASA and China will be able to land people on the Moon, other nations can get rovers/supplies there.

Anything goes wrong on Mars - you are dead. I would pick Moon any day.

[elihu]

Mars has more resources available to work with and is a less extreme environment than the moon or space. There's definitely a trade-off between quick and easy access to the moon versus an easier environment to work with.

No one can survive in any of these places without a space suit, but on Mars you have easier access to the various natural resources you'd need in order to survive and build additional infrastructure. Light for solar power is consistently available on a normal day/night cycle, as is CO2 and water, which can be used to make methane fuel and liquid oxygen. It has concentrations of sulfur, which can be used to make a form of concrete. The gravity is more conducive to long term human health. All this is relevant.

Surviving on the moon or in LEO is also quite possible, it's just that you'd need to bring more equipment and all the resources you can't find on-site.

[hutzlibu]

"Mars would be an easier place to survive, but the moon is easier to get to. "

Since it takes 6 months to get to mars and only 3 days to the moon and the only advantage for surviving on mars is the mini gravity, I really think we should start with the moon.

[elihu]

It's not just the gravity. On the moon, you have to deal with 2 weeks of day and 2 weeks of night, which means having to deal with wide temperature swings and if you rely on solar you need very large batteries.

Mars also has an atmosphere which contains CO2, which is useful for making methane. It also has a lot of water. (The moon has water too, though it may be less abundant/accessible.)

[redblacktree]

Could some of those downsides be mitigated by putting your base on a "pole"?

That is, are there locations on the Moon's surface where the sun is perpetually visible?

[m4rtink]

There are just a few crater rims where this happens, not the full pole - but those do indeed get sunn almost all the time & border areas in perpetual darkness, which is also pretty useful (cryogenics, temperature gradient, etc.).

[elihu]

Sort of; there are some spots that get sunlight almost all the time. (The moon has quite a bit of wobble, so it's hard to get to 100%.) That greatly restricts your choice of base locations, though. There may be other resources or geological features you might want to be close to that aren't convenient (lava tubes, water deposits, flat places to land, minerals that can be used as building materials, etc...).

[redblacktree]

I suppose if our base is extensive enough, we could use those locations primarily for power generation and then transmit that power to more desirable locations for other tasks. Though I do realize that I'm talking about a lot of effort/time/money/resources.

[hutzlibu]

Day and night cycle is an issue yes, and sure, for a long term self sustainable settlement, mars looks much better.

But in terms of setting up a base soon and building rockets for example ... the very short travel distance to the moon offsets any advantage the mars has