It isn't the stay on Mars that is the big problem, but the transit to and
from
which is. Another one is landing and taking off from Mars which has some
atmosphere (moon doesn't) and higher gravity than moon.


Its ALL a issue. from leaving the earth till safe return.

Any fauilure along the way can kill people and the program.

The biggest advantage to the moon base is managing a base away from easy return
to earth or easy resupply.

Managing such a base wether it be moon or mars may be more of a challege than
the tech end.

We can create a moon base much easier than a mars base. While we plan a mars
expedition we should build the moon base just for experience. Besides the moon
exploration wise has barely been touched....