Mount Everest is about 5Â½ miles . Greg Bear : I like to imagine taking a vacation on Mars . He says the thin atmosphere and frigid temperatures make it a harsh environment . After Earth , it 's considered the most hospitable planet for humans in the solar system , he says . Bear : Scientists , artists and nerds have all been fascinated by the story of Mars .
Greg Bear : I like to imagine taking a vacation on Mars . He says the thin atmosphere and frigid temperatures make it a harsh environment . After Earth , it 's considered the most hospitable planet for humans in the solar system , he says . Bear : Scientists , artists and nerds have all been fascinated by the story of Mars .