Twelve things you should know about Carl Sagan

Resumen

He is an American astronomer and pioneer of exobiology or search for extraterrestrial life. In the 50´s he participated as an advisor and consultant to NASA. He worked on the Mariner, Viking, Voyager and Galileo space programs. He was an instructor at the Apollo program; played a decisive role in planetary research: he helped decipher the high temperatures on Venus by using the theory of massive global greenhouse, seasonal changes on Mars and Titan reddish cloudiness.