Project Blue Book United States Air Force program Actions Share Share Share to social media Facebook X URL https://www.britannica.com/topic/Project-Blue-Book Share Share Share to social media Facebook X URL https://www.britannica.com/topic/Project-Blue-Book Written by Michele Metych Michele has a B.A. in English from Southeast Missouri State University and an M.A. from DePaul University. She's a Chicago girl at heart, but she still misses living in a place with farms. When she's not... Michele Metych Fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors. The Editors of Encyclopaedia Britannica Last Updated: Sep 26, 2024 • Article History Table of Contents Ask the Chatbot a Question Ask the Chatbot a Question Project Blue Book, code name for the United States’ longest-running Air Force program dedicated to investigating sightings of UFOs (unidentified flying objects), which ran from 1952 to 1969. The program generated controversy because of its subject matter and the secrecy surrounding its operation. Project Blue Book was the successor of two similar programs. The first was Project Sign, a classified program that tried to explain a number of military-reported UFO sightings and determine whether they were extraterrestrial in origin, while also considering potential threats to national security, especially those related to possible espionage by the Soviet Union. Project Sign lasted ...(100 of 672 words)

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