You bet. What are our lives worth? I think spawning a new world is a fine use.

Also, that "lives" figure is counting the descendants of the people that eventually make a life for themselves on Mars. Those descendants won't get a choice, and one could argue it's unethical to put them in that position. So any analysis of how many lives Mars is worth must take this into account. And if it's anywhere near successful, a few million lives is at the low end.

Yeah, I'm still pissed that my ancestors left England for the Americas in the 1600s. I didn't get any say in the matter and it was totally unethical of them to put me in this position. So selfish. Sad.

Did you also count the amount of lives that could be saved here on earth for the same amount of money.

What about their descendants? (by the way, who has a much better chance of surviving here on earth than in the fragile conditions in what ever planet)...

If you're going for raw cost/benefit, there's a good argument to be made for the cost/benefit ratio of being a multi-planet species safe from planet-killing asteroids etc.

Then don't. But look at human history and you'll find endless examples of people risking everything for causes they believed in. How much is making a real dent in the universe, and being on a list of names that will be revered as long as human records survive worth?

> people risking everything for causes they believed in..

And often have been taken advantage of....Just saying...