When Lue Elizondo was part of the Pentagon's Advanced Aerospace Threat Identification Program (AATIP) he identified five observable characteristics of UFOs, dubbed the "five observables." Season 2, Episode 8, "Extraterrestrial Encounters." #Unidentified Subscribe for more from Unidentified 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://www.history.com/shows/unidentified-inside-americas-ufo-investigation Check out exclusive The HISTORY Channel content: History Newsletter - https://histv.co/newsletter Website - https://histv.co/History Facebook - https://histv.co/Facebook Twitter - https://histv.co/Twitter In season two, each episode will center around a specific case or aspect of the modern UAP phenomenon and follow the credible team of connected investigators including former military intelligence official and Special Agent In-Charge, Luis Elizondo, and former Deputy Assistant Secretary of Defense and Intelligence, Chris Mellon. The HISTORY® Channel, a division of A+E Networks, is the premier destination for historical storytelling. From best-in-class documentary events, to a signature slate of industry leading nonfiction series and premium fact-based scripted programming, The HISTORY® Channel serves as the most trustworthy source of informational entertainment in media. The HISTORY® channel has been named the #1 U.S. TV network in buzz for seven consecutive years by YouGov BrandIndex, and a top favorite TV network by Beta Research Corporation. For a deeper dive, visit history.com or follow @history on Instagram, Twitter, Facebook, YouTube and TikTok. For additional press materials visit the A+E Networks Press Center at http://press.aenetworks.com.