Well, I agree that it's nice to dream, but between ourselves and these dreams there's the real world with very real and difficult problems. High energy cosmic radiation is one of them. One trip to Mars alone would expose you to a dose of radiation comparable to what some astronauts take in their whole career.

This is one of the many reasons why I can't be that overly excited about the discovery of a seemingly nice planet several light years away. There's a decent one right next door that is yet way out of reach.