In 1976, Carl Sagan became the David Duncan Professor of what field?

In 1976, Carl Sagan became the David Duncan Professor of Astronomy and Space Sciences.

The professorship was at Cornell University, where Sagan had joined the faculty after Harvard denied him tenure in 1968. He became a full professor in 1970 and directed Cornell's Laboratory for Planetary Studies, building an unusually broad career across planetary science, astronomy, cosmology, and the search for extraterrestrial life.

The title is sometimes shortened informally to “astronomy professor,” but its formal wording matters: “Astronomy and Space Sciences” is the canonical field named in biographical accounts. Sagan held the David Duncan Professorship for the rest of his life, while also becoming one of the most prominent public explainers of science through books and the 1980 television series Cosmos.