Terraforming Mars

From: jim.piunti

> Most of us who were 'raised' on the O'Neill/Heppenheimer philosophy
> probably feel, as I do, that terraforming isn't way to go - and it
> doesn't have anything to do with the 'morality' of using another
world,
> with its own potential indigenous 'life forms' - it has to do with the

> non-necessity of subjecting ourselves to yet another gravity well,
with
> its own inherent problems.

Yeah, I wrote an article on this very subject: The Case for Space
http://writings.mike-combs.com/case_spc.htm

> Question: I know that the moon can supply us with the vast majority of

> building materials we'll need for habitats, but thinking long term,
> will it and the asteroids be able to provide us with *everything* a
> human colony would need? Or will we still have to 'import' certain
> materials from earth and/or other planets?

My attitude is that Mars provides very little or nothing that couldn't
be had from the right combination of asteroids. The two big things that
Mars aficionados tend to point to is water, and carbon from the CO2
atmosphere. But Carbonaceous Chondritic asteroids are obviously good
sources of carbon, and can be 10-20% water by weight.

I've heard arguments that only on Mars will water-based geological
ore-concentration processes have produced useful concentrations of
elements like copper or uranium. Number one; this is speculative until
we have ground truth. Number two; I think aluminum (plentiful on the
moon) can replace copper for most applications, and I doubt that the
people living outside the shadow of a planet will have much use for
uranium as a power source. (They might have some use for it if
interested in nuclear rockets.) But even if this point is valid, things
like copper and uranium represent very small percentages of what we need
in comparison to materials like steel and glass and concrete.

I've heard a case made for harvesting nitrogen from the atmosphere of
Mars for sale to orbital habitats. I'd have to admit that I've more
recently come to accept that even CC-type asteroids are not quite as
chock full of nitrogen as I'd been lead to believe as a youngster. The
point was made that nitrogen can be usefully concentrated in planetary
atmospheres in comparison to other gasses due to its tendency to NOT
react readily. So although I've had a tendency to totally dismiss
planets as sources of raw materials of any kind, I might have to allow
that a possible exception might be nitrogen, at least until that era
when we're harvesting ice from so far out into the Solar System that
useful amounts of ammonia can be found in it. That said, I still can't
help but wonder if some point to the atmosphere of Mars as a source of
nitrogen for atmosphere dilutant in space habitats because they're
pulling for development of Mars and are desperate to come up with
anything which might conceivably be an economical export.

Regards,

Mike Combs