I don't think mankind is going to colonize any other planet or moon. Especially not at a rate where we could abandon Earth after we run out of whatever the next scary thing it. Our species will die on this planet some day, probably not any time soon, definitely not in any of our lifetimes. I don't think the colonization of alien planets should even be on the radar of our space program. Easier to just fix Earth. As inhabitable as Earth seems to you, Mars and the moon are even more inhabitable. Infinitely so. As far as private space exploration companies, as far as I know they are basically a tour bus that barely exits the Earth's atmosphere for a shirt while and then lands. REAL space exploration is not for tourists. REAL space exploration thus far isn't even profitable and real investors aren't even interested in retrieving a small number of samples from the moon for analysis. Where do I think NASA should be right now? I don't know a whole lot about their study on other planets or what benefits those studies have brought to mankind, but I am very interested in Japan's plan to launch a giant solar panel into orbit and I think we should be looking into that. I don't care all that much though because if we did do that as a nation it would be handed over to private interests who would gouge us just the same as they would no matter where our energy comes from so screw it.