Greg Bear : I like to imagine taking a vacation on Mars . Phobos is blacker than sin , blacker than soot , but still visible to my naked , freezing eye . He says the thin atmosphere and frigid temperatures make it a harsh environment . Robert Zubrin : Bear : Scientists , writers 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 . Robert Zubrin : Bear : Scientists , writers and nerds have all been fascinated by the story of Mars .