At which university did Carl Sagan teach as an assistant professor before joining Cornell?

Carl Sagan taught as an assistant professor at Harvard University before joining Cornell. He joined Harvard’s astronomy faculty in 1962 and remained there until 1968, when he moved to Cornell after being denied tenure at Harvard.

Sagan’s Harvard years followed research work at the University of California, Berkeley, and a brief appointment as a visiting assistant professor of genetics at Stanford Medical School. Those earlier positions can cause confusion, but Harvard was the university where he held the assistant professorship in astronomy referenced here.

At Cornell, Sagan became a full professor in 1970 and directed the Laboratory for Planetary Studies. He stayed there for the rest of his career, becoming one of the university’s best-known public intellectuals through books, television, and planetary-science research. His path from Harvard to Cornell was therefore a major transition in both his academic career and his rise as a science communicator.