Saw this on the BBC this evening, and thought you might find it interesting, both for the content and for the mind boggling zoom capability of the webpage.
HTwins.net - The Scale of the Universe
HTwins.net - The Scale of the Universe
We should have moon colonies by now and ironically the Apollo program is probably the most at fault for that. In order to make it happen a lot of political capital was expended, creating a particular political situation which has become a permanent institution within NASA manned spaceflight (specifically, billions of federal dollars flowing into a few very specific congressional districts which has continued through Apollo and Shuttle programs and now SLS/Orion). If NASA had instead concentrated on a slower program which built up long-lived infrastructure and optimized toward lowering launch costs and increasing capabilities then we would easily have cities (or at least towns) in orbit and moonbases, and Mars bases.