This story appears in the August 2017 issue of National Geographic magazine. Carl Sagan spent his childhood immersed in Mars. The future scientist, an avid reader of Edgar Rice Burroughs’s ...

Carl Sagan with the ... But as Cosmos fans know, Sagan's starry-eyed sci-fi hopes never beat his hard-edged science. He shot down one early "proof" of life on Mars. He predicted the surface ...