My father was not only a planetary scientist and a great popularizer of science, but he thought very deeply about the world.… — Nick Sagan Copy Share Image
As a planetary scientist, I don't know what else to call Pluto: It's big and round and thousands of miles wide. — Alan Stern Copy Share Image
To say that what a planet is doesn't matter would be to imply that a planetary scientist couldn't explain to someone what… — Alan Stern Copy Share Image
