Could extraterrestrials be keeping an eye on America? Find out in this Ancient Aliens compilation! Watch your favorite episodes of Ancient Aliens on The HISTORY Channel website at http://history.com/schedule. #AncientAliens Subscribe for more from Ancient Aliens and other great The HISTORY ...

Could this layer of ash found beneath the Earth's soil be evidence of a major global event? See more in this scene from Season 2, Episode 8, "Aliens and Mysterious Texts." Watch your favorite episodes of Ancient Aliens on The HISTORY Channel website at http://history.com/schedule. ...