If extraterrestrials are watching over humanity, Ancient Astronaut Theorists suggest the next great global catastrophe could be caused by our heavenly ancestors in this clip from Season 9, "The Great Flood". #AncientAliens Subscribe for more from Ancient Aliens and other great HISTORY shows: ...

Tune in to Alien Invasion Week on History starting Monday 9/30 through Friday 10/4 for new Ancient Aliens, plus the premiere of In Search Of, new UFO Specials and More! Ancient Astronaut Theorists claim that extraterrestrials influenced the outcome of the Civil War and made believers out of ...