Mars vs settlements.

> One thing I never seem to get about this idea of "terraforming"
> Mars, is that as I understand it the planet hasn't got an earth-
> like atmosphere because it is not able to retain it, lacking in
> gravitational mass and magnetic fields powerful enough...
> Do I get this horribly wrong, or otherwise what is the point of
> giving the planet an atmosphere (assuming it is possible of
> course!) if it will loose it very rapidly again anyway?

The idea is that Mars will lose said atmosphere, but very slowly.
Slowly as in hundreds of thousands of years. Plenty of time to top
off every now and then.

Xenophile (not sure how to give Mars a magnetic field, or if it needs
one)