Project Blue Book

The Air Force's long-running study of UFO reports, run from its Wright-Patterson base. The National Archives counts 12,618 sightings reported to it from 1947 to 1969.

Project Blue Book was the Air Force's study of UFO reports, headquartered at the Wright-Patterson base. Newsweek says it grew out of an earlier effort, Project Sign, set up after a wave of sightings in 1947. One of those was the pilot Kenneth Arnold's report of nine objects in formation passing Mt. Rainier in Washington, moving at three times the speed of any known crewed aircraft by his estimate.

The astronomer J. Allen Hynek served as the project's consultant. In his own account, staff from Wright-Patterson's technical center, in Dayton, some 60 miles off, visited him and, somewhat embarrassed, asked whether he would advise the Air Force on flying saucers. He agreed, expecting the work to take little time.

By the end, the project had logged 12,618 reports from 1947 to 1969, the National Archives says, and 701 of them stayed classed as unidentified. Wikipedia says the project put most reports down to clouds, stars and other natural causes, or to ordinary aircraft. Personnel at the base have since stopped taking UFO reports, per the archives.

Gerald Haines, a CIA historian, wrote in 1997 that Blue Book investigators who knew about secret U-2 flights traced many sightings to them, after consulting the agency's staff running the U-2 project. He says they kept that explanation from the public and pointed instead to natural effects like temperature inversions or ice crystals. Newsweek reported in 2019 that the project had become the basis of a History Channel TV series that took its name.