The CO2 atmosphere at the surface of Mars has a pressure of around one
hundredth of sea level pressure here on earth. Actually, the CO2 partial
pressure on Mars might be similar to that on earth, but the big problem is
that liquid water will not hang around for long at this atmospheric
pressure, it will be either solid or gaseous depending on temperature. The
water in any (earth like) higher plant cell on Mars will either freeze and
disrupt the cell contents or it will boil and burst the cell walls. Maybe at
some depth below the surface things might be more conducive to plant growth
if an alternative to solar input could be found for an energy source. Or
maybe plants could one day be grown under pressurised domes.

However, my scepticism to most Terraforming ideas arises from the fact that
we have a perfectly good Earthlike ecosystem here on Earth, and we can't
even maintain that. So what chance do we have of constructing one from
nothing?

Sally

"Andrew McKay" wrote in message
...
I was musing about the following situation, maybe someone can offer
some thoughts?

WRT to Mars my current understanding is that the climate is harshly
carbon dioxide (is it?). If it is then we know that trees and plants
can change carbon dioxide into more friendly climatic gasses for human
habitation.

So if there were water deposits found on Mars, how viable would it be
to engineer some serious vegetation on the planet so that the
atmosphere starts to develop more human friendliness? Obviously the
vegetation would also need its own life support systems such as
insects and so on, so it would generally take rather more than a
packet of seeds from the garden centre.

I appreciate it's not an overnight change, and it could in fact be
hundreds of years (or longer) before the climate was friendly enough
to support human life.

The question is purely rhetorical as I'm interested to know if this
would be a feasible option.

Andrew

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