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 ...

Dr. Sagan, a planetary scientist who was recognized for both his ingenious scientific ideas as well as his enormous influence in popularizing space science, was a new member of the SETI Institute’s ...

Carl Sagan told us that there are more stars in the universe than there are grains of sand on all of the Earth's beaches. At the same time, there are more H 2 O molecules in just 10 drops of water ...

Let’s conclude this discussion with two handy quotes from Carl Sagan. First, in case you are wondering why I dragged you through a historical prediction from the 1970s, I would like to proffer ...