Some Ancient Astronaut Theorists suggest that deep within our own planet could be another earth in this clip from Season 10, Episode 6, "The Other Earth". #AncientAliens Subscribe for more from Ancient Aliens and other great HISTORY shows: http://histv.co/SubscribeHistoryYT Find out more about the show and watch full episodes on our site: http://po.st/AncientAliens Check out exclusive HISTORY content: History Newsletter: http://po.st/HistoryNewsletter Website - http://po.st/HistoryWeb Facebook - http://po.st/HistoryFacebook Twitter - http://po.st/HistoryTwitter "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.