Whenever anyone has said something technologically possible is impossible for the human race, they have, so far, been proven wrong (in the last few hundred years, usually within their own lifetimes... in the last few decades, often within years or months of the pronouncement. Remember the head of DEC (Digital Equipment Corp... does anyone remember them?) saying that he could think of no reason why anyone would ever want to own a personal computer? That is just one of many such pronouncements. I hope this follows the pattern and we start terraforming our Moon, Mars and the suitable moons of the gas giants within the next few years. I was born in 1947 and would volunteer for such an expedition in a heartbeat. I suspect many more of my fellow denizens of this lovely planet feel the same way.