Sagan refers to Carl Sagan, an American astronomer, astrophysicist, cosmologist, author, and science communicator. He is best known for popularizing science through his books and television series, including "Cosmos: A Personal Voyage." Sagan was a prominent figure in the scientific community and was well-known for his contributions to the study of planetary science, including his involvement in numerous NASA missions. He was also an advocate for scientific skepticism and critical thinking, and his work has had a lasting impact on popular culture. Sagan passed away in 1996 at the age of 62.