The following are the top 5 instances of government cover-ups regarding alien activity. 00:00 The Navy, Nuclear Weapons and UFOs 04:15 Inexplicable Flying Objects 08:41 US Government Sees More than We Know 12:34 Project Blue Book Attempts to Prove UFO Phenomenon 16:47 The Roswell Incident 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 Ancient Aliens and other great The HISTORY Channel shows: http://histv.co/SubscribeHistoryYT Find out more about the show and watch full episodes on our site: https://histv.co/AncientAliens Check out exclusive HISTORY content: History Newsletter - https://histv.co/newsletter Website - https://histv.co/History Facebook - https://histv.co/Facebook Twitter - https://histv.co/Twitter "Ancient Aliens" explores the controversial theory that extraterrestrials have visited Earth for millions of years. HISTORY® is the leading destination for award-winning original series and specials that connect viewers with history in an informative, immersive, and entertaining manner across all platforms. The network’s all-original programming slate features a roster of hit series, premium documentaries, and scripted event programming.