Carl Edward Sagan (1934 – 1996) ~ American astronomer, planetary scientist and science communicator. He was one of the most well-known scientist of the 1970's and 1980's . He was controversial in scientific, political, and religious circles for his views on extraterrestrial intelligence, nuclear weapons, and religion. His best known scientific contribution is his research on the possibility of extraterrestrial life. He was an advocate for nuclear disarmament and co-wrote and hosted 'Cosmos: A Personal Voyage.' He was widely regarded as a freethinker and one of his most famous quotations, in Cosmos, was, "Extraordinary claims require extraordinary evidence.