In days gone by, scientists would speak solemnly about our solar system's 'habitable zone' - a theoretical region extending from Venus to Mars, but perhaps not encompassing either, where a planet would be the right temperature to have liquid water… — Seth Shostak Copy Share Image
We have one planet in our solar system that's habitable, and that's the Earth, and space travel can transform things back here for the better. First of all, by just having people go to space and look back on this… — Richard Branson Copy Share Image
