[optforfon]

It has an "atmosphere" It's 0.00628 atm according to Wikipedia. That's effectively a vacuum. You can't have liquid water on Mars.

So you can grow plants in some kind of transparent pressurized place... Just like on the Moon.. or on a space station

[ncallaway]

You can pressurize a chamber using the thin atmosphere, rather than being restricted to the gasses you bring with you.

You can use ISRU and atmosphere resource extraction to generate rocket fuel on the surface of mars, rather than being restricted to the rocket fuel you bring with you.

Ultimately, the answer is Mars has the necessary resources and when you look into the details just makes more sense and is easier.

[aggie]

You can produce fuel from lunar regolith as well.

http://www.wickmanspacecraft.com/lsp.html

[Symmetry]

But it's still much easier to grab even a thin gas than it is to mine anything. An extremely convenient source of both carbon and nitrogen is going to be a huge benefit in terms of trying for long term sustainability. The Moon does have plenty of oxygen in various minerals and hydrogen in the polar ice but you need more than that.

[zardo]

>That's effectively a vacuum.

That depends entirely on the effect in question.

You'd have a hard time pressurizing the moon's atmosphere to harvest it for propellent.

[baq]

this effective vacuum gives a 10m column of water equivalent of radiation protection. you'll really like it compared to the moon.