[dennisgorelik]

1) It's much cheaper protect yourself from nuclear war and meteors while staying on the Earth (e.g. digging down) than move to the Moon. Moving to Mars/Venus is even worse than Moon.

2) If you want to "insure" our civilization from disappearance -- focus on developing smart machines that can travel anywhere and carry our civilization accomplishments to other places. Sending people to other planets/asteroids is extremely inefficient in comparison with other options.