[epaladin]

It's also kind of vital for the balance of the planet's ecosystems, as we're slowly finding out. If we melt it to get materials under there, there's a sizable chance of long term regret.

Whereas Mars doesn't have an ecosystem at present and no species to endanger.

I want to make other planets livable so we can stop killing this one so much.

[dragonwriter]

> I want to make other planets livable so we can stop killing this one so much.

What (insufficient thought it might be) political support there is for efforts to stop killing this planet is based largely on the idea that "its the only one we have", so I'm not sure that really works.

[pcrh]

I would certainly be in favor of terraforming Mars, and then seeing what could be done.

One might (or might not...) want to wait until we have clear evidence that it is indeed sterile. In either case the first thing to do would be to seed it with engineered robust lichens, or the like, just to get things started.