But the narrative fits so well into our disposable society, use up one planet, move on to the next. We've screwed up this planet, why do we believe we have the technology to rehabilitate a planet in far worse shape than Earth? It's just so sexy to talk of another inhabiting another planet and so pedestrian to fix this one. It might make sense if Mars was a mirror image of Earth, but Mars better resembles hell. I’m glad there is not another Earth close by. It would be a shame to let humans despoil another planet.