Reply #17: biospheres need power

[qazplm]

they need power for creating heat, possibly oxygen, water, shielding for cosmic rays, etc.

It's too easy in oh so many ways to sabotage by accident or on purpose.

A lot harder than a terraformed planet. I also think it isn't as difficult to terraform as you assert. I think we it's doable. Drop a few ice comets on Mars and you've introduced a bit of water and heated up the planet enough to possibly create a tentative atmosphere. I guess my point is that we can already speculate how to do it, once you can figure out how to do something, it usually ends up being done sooner or later.