Comment Re:Find precious metals on Mars (Score 1) 228
You do realise that there are some planets in our own solar system, right? The summary mentions them..
Colonies around other stars can wait for a long time, since we only need those to protect against really really huge disasters like supernovae or the sun going out. Those aren't going to happen for a VERY long time, so we can ignore other stars for now.
What we need is self sustaining colonies off Earth, but near enough to be able to interact with Earth, hear Earth's messages, learn Earth's lessons.
The threat we're guarding against is that of having a vast number of people stuck in a single biosphere, all complex unpredictable people, occasionally inventing new and dangerous things. A few decades ago, nuclear war seemed like the manifestation of that. We got past that hurdle with civilisation intact. How many more inventions like that will there be? How many times can we pass the test?