I don't think we know how to do the latter, in terms of colonization. Our experience locally is that living in hazardous environments is not something human bei

I don't think we know how to do the latter, in terms of colonization. Our experience locally is that living in hazardous environments is not something human beings can endure long term. We'd be asking people to live in a place that combines the worst elements of submarine and Antarctic living, with no real way of responding to any difficulty at all, even through communication. Lot of people assume magical science fairies will solve this via "terraforming" or some other science fiction only idea, but more likely space exploration will remain unmanned probes if just because we aren't going to send a generation of explorers to their deaths or eventual madness.