From The History Channel : "If ancient aliens visited Earth, what was their legacy, and did they leave behind clues that exist in plain sight such as sophisticated aircraft, complex electrical grids, and intricate construction machinery?...
Aired: Apr 20, 2010 From The History Channel : "If ancient aliens visited Earth, what was their l...
Aired: Apr 27, 2010 From The History Channel : "If ancient aliens visited Earth, who were they, a...
Aired: May 4, 2010 From The History Channel : "If ancient aliens visited Earth, what was their m...
Aired: May 18, 2010 From The History Channel : "Reports of encounters with strange beings and sig...
Aired: May 25, 2010 From The History Channel : "There is evidence that suggests we experienced 20...
Streaming in:
Main Cast
Appearances
Creators
Current Status: Returning Series
Network: History
Genres: Sci-Fi, Documentary, History
