Walter Seager Sullivan, Jr. (January 12, 1918 – March 19, 1996) was considered the "dean" of science writers.
Over a 50-year career, he covered all aspects of science ‒Antarctic expeditions, rocket launchings in the late 1950s, physics, chemistry, and geology.
He wrote several well-received books, including Assault on the Unknown about the International Geophysical Year; We Are Not Alone, a bestseller about the search for extraterrestrial intelligence; Continents in Motion; Black Holes: The Edge of Space, the End of Time; and Landprints.
In 1971, Sullivan participated in a symposium on the occasion of the arrival of Mariner 9 to Mars, together with Ray Bradbury; Arthur C. Clarke; Carl Sagan and Bruce C. Murray.
In 1980, Sullivan was awarded the Public Welfare Medal from the National Academy of Sciences.