When astronomers first picked up a perfectly regular radio heartbeat from deep space in 1967, some of them half-jokingly labeled it a message from “little green men.” That signal, from a spinning ...

In 1967, astronomers thought they had finally heard from the neighbors. They intercepted a signal so regular and precise it seemed impossible for it to be natural. But the excitement didn’t last.

In his classic science fiction novel Contact, Carl Sagan remarked, “The universe is a pretty big place. If it's just us, seems like an awful waste of space.” Physicist Enrico Fermi is credited with ...

In 1950, famed astrophysicist Enrico Fermi posed a profound question during a casual lunch with colleagues: Where is everybody? In other words, if there’s an extremely high probability that advanced ...