The Why Files S04 E20 Aliens & Espionage: Crop Circles and the CIA Coverup | They Don't Want You to Know

In 1974 a group of scientists beamed a message into space. The message, meant to be received by an intelligent alien species, described life on Earth. Written in simple binary code, and using the most powerful radio telescope on the planet, the message was broadcast to a dense cluster of stars in the constellation of Hercules.