He was a Russian-born American writer and professor of biochemistry at Boston University. He lived between January 2, 1920 – April 6, 1992. During his lifetime, he was considered one of the "Big Three" science fiction writers, along with Robert A. Heinlein and Arthur C. Clarke.
He also wrote an estimated 90,000 letters and postcards. Best known for his hard science fiction, Asimov also wrote mysteries and fantasy, as well as much nonfiction.