On Aug/8/2018 at 10:00 PM, Scott M. Kozel wrote :
On Wednesday, August 8, 2018 at 7:34:07 AM UTC-4, Jeff Findley wrote:
In article ,
says...

I forget how many octillion tons of oxygen it would take, but the
problem is getting it there in the needed quantities and then keeping
it there. Apparently nearly all of its atmosphere (even assuming it was
Earthlike at one time) has long since departed due to the effects of
gravity and solar radiation.

Keeping it there isn't much of a problem. In the short term (hundreds
of thousands of years) it won't lose enough to matter. A few more
Kuiper belt objects would make up for the loss.

So the idea is that they spend a decade or so "pumping it up" to Earthlike
atmosphere, and then that will last for millions of years before it leaks
away?

That's about it. I would change the word decade for century. There is
also a little more to terraforming Mars than adding an atmosphere, but
that is the bulk of it. You would also want to add water, which would
probably be a side effect of adding the atmosphere. Then you want to
grow plants. Before you can say that Mars has been terraformed you want
plants to have been growing plants for a century to add O2 to the
atmosphere and a layer of topsoil.


Alain Fournier