Disclosure Day ends with humanity finally learning the truth about alien life, but the film's biggest surprise comes from the message the extraterrestrials deliver as the world stands on the brink of war.

How Radio Astronomy Helps Us See the Invisible Cosmos," astrophysicist Emma Chapman describes the hidden corners of space that only radio waves can reveal — and makes the case for contacting aliens.

The moment of first contact with extraterrestrials is a staple of science fiction. It usually involves a frantic scientist having a Eureka moment, realising in a single dramatic instant that Earth is being visited by creatures from light-years away.