How could humans terraform the moon or mars so it could sustain life as we know it?

Answer 1

sorry, but people over look the fact that these objects DO NOT have a strong enough magnetic field to protect the "man made" atmospheres we'd create.

http://science.nasa.gov/headlines/y2001/ast31jan_1.htm

The solar winds would basically just blow the atmospheres into space like dust over a period of about 2 - 4 years

sorry, You'll need to find a way to heat up each of their cores.
I don't know how you could safely direct that much energy and do it without creating drastic volatile reactions on the surface.

Answer 2

We couldn't.

It doesn't have an atmosphere, for a start.

Still... I have to disagree with stork5100 - terraforming might be science fiction now but then so was flying in a plane and going to the moon.

I once read a science fiction novel by Wil McCarthy whose books have a lot of hard science in them and one of the themes was terraforming the moon in a time when humanity was running out of space, cursed by its own success. They used superdense materials to reduce the moon to about a third of its normal volume. Increasing the gravity to something similar to earth. Then they could pump atmosphere up there or more easily perhaps, send a few asteroids towards it hopefully heavy in water and methane. Genetically engineered bacteria could produce oxygen. I don't know if the moon would have enough nutrients in it.

I expect for several centuries at least, we'll have at most, enclosed bases with independent air supplies. The old bubble dome cities of 1950's sci-fi.

Answer 3

The moon cannot really be terraformed: there is not enough gravity to keep a stable atmosphere.
Mars would be a bit easier, but would require bringing a lot of gas to form a substancial atmosphere. I will not go into the details, as the link proposed already address those points adequately.
One thing is for sure: doing it would require very deep pockets...

Answer 4

We already have a planet that supports life as we know it. It's called Earth.

Neither the Moon nor Mars have the gravity necessary to maintain an Earth-like atmosphere. If they did, they'd already have one wouldn't they? And without an atmosphere, liquid water is pretty much not an option either.

Terraforming other planets is purely science fiction.