Carl Sagan, the astronomer ... space travel for Contact sparked a whole new direction in research on time travel. How does that make you feel? Hear Sagan via RealAudio Sagan: I find it marvellous ...

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 ...