Africa's Extraterrestrial Contact-S20/E15

 The origins of humanity can be traced back to Africa, and some of the oldest religious traditions across the continent describe mysterious beings who descended from the sky in thunderous vehicles.

Alien Investigators-S20/E14

 Host Giorgio Tsoukalos opens the series archives to celebrate ALIEN INVESTIGATORS that have been brave enough to ask the question, "Are we alone in the universe?" Could these investigators have uncovered proof of an alien presence on earth?

Secrets of the Amazon-S20/E13

 The Amazon rainforest remains largely unexplored, but thanks to new technology, researchers are now finding that this dense jungle was once home to a vast network of cities.

Hidden Messages-S20/E12

 From colossal figures that can only be seen from the sky to complex crop circles that mimic sound frequencies, and mathematical messages encoded on opposite sides of the planet, could these sites hold clues about alien visitation?

Alien A.I.-S20/E11

 
The rapid development of artificial intelligence has made it a powerful tool for historians and archaeologists. But might it also reveal evidence of an extraterrestrial presence on Earth?