Subscribe and 🔔 to the BBC 👉 https://bit.ly/BBCYouTubeSub Watch the BBC first on iPlayer 👉 https://bbc.in/iPlayer-Home What if we're not alone? 👽 In this drama-documentary, the discovery of a mysterious alien object leads people to challenge everything they thought they knew about life and ...

Subscribe and 🔔 to OFFICIAL BBC YouTube 👉 https://bit.ly/2IXqEIn Stream original BBC programmes FIRST on BBC iPlayer 👉 https://bbc.in/2J18jYJ Professor Brian Cox visits the people who run SETI - the Search for Extraterrestrial Intelligence - and investigates whether we once received a signal ...