When she was just four years old, Shanti Devi began telling her parents eerily specific details about her old life in a town 75 miles from where she was born — and a place she'd never been to before.

James Morison claimed that his vegetable pills could cure anything from smallpox to dysentery — and thousands of British people believed him.

As soon as humans had telescopes strong enough to study Mars in detail, we've asked ourselves two questions: Does Mars have life? How can we establish contact?