🚀 go-pugleaf

> In Vol. 7, Nr. 29 of Space Digest, Henry Spencer claimed that the
> existence of **all** the elements on Mars necessary for life and the
> industrial development of Mars is unproven...

I don't have archives that go that far back, but as I recall, my skepticism
was directed at the presence of things like ore bodies, not at the existence
of some of the more common elements.

> [Viking lander data]

The Vikings gave us data on the first few centimeters of surface in two
small areas.  The close agreement between the two is heartening, but it's
still awfully thin evidence to base industrialization on.  In particular,
we have no idea whether that is the bulk composition or just that of the
surface; this matters quite a bit.  Topsoil is not really representative
of the bulk composition of the Earth's crust.

> All of the elements necessary to support life exist on Mars.  However
> based on this evidence, Mars does lack some elements necessary for
> human health and those are:  Iodine and Phosphorus...

Based on this evidence, it lacks quite a few in fact.  A surprising number
of elements are needed for human health, albeit many of them only in trace
quantities.  The percentage of cobalt, for example, in the human body is
minute... but no cobalt equals no vitamin B12 equals death from pernicious
[?] anemia.  Much more serious than trace elements or even relatively minor
ones like phosphorus is the distinct shortage of hydrogen -- water is not a
trace requirement!  There is probably quite a bit of water in Martian
permafrost, but we don't know that for sure.

> The extreme richness in iron is particularly exciting...

A fair bit of iron, yes, but I wouldn't call it "extreme richness", not
when comparing it to things like nickel-iron asteroids.

> So there you have it.  Mars is a rich planet for industrialization.

It may be about as good as any planet, apart from the shortage of
water and the annoyingly thin atmosphere.  It still has all the problems
of planets as industrial bases in general:  inescapable gravitational
fields, atmosphere that is hard to exclude, a deep gravity well that
(particularly in combination with the atmosphere) makes transportation
expensive, daily and seasonal temperature cycles, unavailability of solar
power during the night.  Mars also has a couple of problems of its own:
surface roughness and dust storms.  Mars makes Earth look flat; its terrain
is a major challenge to transportation systems, especially in active areas
like the neighborhood of the polar caps -- an area otherwise very interesting
because of probable ample supplies of water.  And it has dust storms on a
planetary scale, very long-lived and widespread.  They are bad news for solar
power -- those storms are pretty opaque, from the Viking data -- and I believe
they also chill the surface pretty thoroughly.  I also doubt that spacecraft
would find landing or taking off in a dust storm particularly safe.  Mars
may be a rich planet, but it's got some real problems as an industrial base.

"Is the surface of a planet the best place for an expanding industrial
civilization?"  -- Gerard O'Neill     "No."  -- ibid
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,decvax,pyramid}!utzoo!henry