Re: [OT} Terraforming

>Actually what I mean is:
>Say humans land on a world with a respectable amount of
>atmosphere and water, but no life.  You can break up some
>rock and add organics (compost) to get soil, but obviously
>you can't add enough organics to get topsoil for the entire
>planet.  Therefore you use....what?  Algae?  Lichen?  What
>breaks down the rock, and how long does it take?

Well, there's actually one problem with that- oxygen is VERY reactive.
Normally, it bonds to metals, rocks, and everything else until it's
gone. The only mechanisms we know of that result in free oxygen in an
atmosphere are organic (ie life). Therefore, if you find a lifeless
world, it's likely to have a reducing atmosphere (methane and so forth).
An infusion of bacteria and photosynthetic airborn microbes will start
your terraforming process, but it's going to take a LONG time....

Brian Quirt