From its earliest days, science fiction has asked whether or not we're alone in the universe. Steven Spielberg, Ridley Scott, Sigourney Weaver and others ponder the question: What can aliens teach us about ourselves?

Science fiction's fascination with the possibilities of outer space.

From Frankenstein to Stranger Things, what terrifies us about monsters in science fiction? Guillermo del Toro, Ridley Scott, Milla Jovovich and others explore why we like being scared so much.

Steven Spielberg, Christopher Nolan, Robert Kirkman and others explore what happens... when the world goes to hell? How does science fiction imagine the end will come about? And could I survive?

Technology is at the heart of science fiction. Steven Spielberg, Arnold Schwarzenegger, George Lucas and others attempt to answer the question: Will the smart machines that science fiction predicted save humankind or lead to our demise?

Christopher Nolan, Keanu Reeves, Christopher Lloyd and others take a look at how, in science fiction, time travel offers the chance to correct history's mistakes... while creating entirely new ones.