It’s a question humans have asked forever. Are we alone in space? But it wasn’t until the late 1960s that humans started an organised, systematic hunt for extra-terrestrial intelligent life. We have listened to radio waves, peered through the celestial dust and beamed The Beatles to distant planets. So how’s it going? Is there anybody out there? This is the story of the search for extra-terrestrial life.

Presenter: Helena Merriman

(Photo: The ALMA, an international partnership project between Europe, North America and East Asia, with the cooperation of Chile. Credit to Getty)