He didn't tell anyone what he saw for YEARS. See more in this scene from Season 19, Episode 5, "The MUFON Files." Watch all new episodes of Ancient Aliens, Fridays, at 9/8c, and next day on The HISTORY Channel website at http://history.com/schedule. #AncientAliens Subscribe for more from ...

Rumor has it there's been an alien employed at Area 51. See more in this scene from Season 19, Episode 7, "Close Encounters of the Fifth Kind." Watch all new episodes of Ancient Aliens, Fridays, at 9/8c, and next day on The HISTORY Channel website at http://history.com/schedule. ...

The vast Alaskan wilderness is well known for mysterious disappearances, electromagnetic anomalies, stories of strange creatures, and is a hotspot for UFO sightings. Could Alaska's many mysteries be due to a presence that is not of this world? Find out in this clip from Season 19, Episode 8, ...

Was this CIA member killed because he wasn't supposed to see something at the base of Mt. Hayes in Alaska? See more in this scene from Season 19, Episode 8, "The Mysteries of Alaska." Watch your favorite episodes of Ancient Aliens on The HISTORY Channel website at http://history.com/schedule. ...

How could these massive ancient structures have been made without the help of giants?! See more in Season 19, Episode 10, "The Giants of Malta." Watch all new episodes of Ancient Aliens, Fridays, at 9/8c, and next day on The HISTORY Channel website at http://history.com/schedule. ...

Could this technology come from an extraterrestrial origin? See more in these clips from Season 19, Episode 12, "The Top Ten Mysterious Devices." 00:00 Temple Mount, Jerusalem 02:41 Aegean Sea 07:21 Mt. Sinai, Egypt Watch your favorite episodes of Ancient Aliens on The HISTORY Channel ...

More than 3,000 years ago, the ancient Greeks built an empire that is considered the birthplace of Western Civilization, and they credited their most monumental achievements to gods like Zeus, Apollo, and Poseidon. See more in this scene from Season 19, Episode 16, "The Gods of Greece." Watch ...

Did you know that there's a network of private citizens that investigate UFOs? See more in this scene from Season 19, Episode 5, "The MUFON Files." Watch all new episodes of Ancient Aliens, Fridays, at 9/8c, and next day on The HISTORY Channel website at http://history.com/schedule. ...