Carl Sagan
Carl Edward Sagan (/ ˈ s eɪ ɡ ən /; November 9, 1934 – December 20, 1996) was an American astronomer, planetary scientist, cosmologist, astrophysicist, astrobiologist, author, and science communicator.His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.