Knowledge Tree
Project Blue Book
Also known as: Blue Book
Facts (42)
Sources
How the Pentagon Started Taking U.F.O.s Seriously | The New Yorker newyorker.com Apr 30, 2021 20 facts
referenceIn 1972, J. Allen Hynek published "The UFO Experience: A Scientific Enquiry," which served as a critique of Project Blue Book and the Condon Report.
measurementOver seventeen years, Project Blue Book reviewed approximately twelve thousand cases, of which seven hundred and one remained unexplained.
accountProject Blue Book was shut down in January 1970.
measurementNinety-five percent of reported U.F.O. sightings investigated by Project Blue Book were attributed to conventional causes such as uncommon clouds, weather balloons, atmospheric temperature inversions, Venus, or classified military technology like the U-2 spy plane and the SR-71 Blackbird.
accountJ. Allen Hynek, an Ohio State astronomer and former member of the Robertson panel, served as the only in-house scientist for Project Blue Book.
accountProject Blue Book was a continuation of Project Sign and operated out of Wright-Patterson Air Force Base near Dayton, Ohio.
measurementOver seventeen years, Project Blue Book reviewed approximately 12,000 cases, of which 701 remained unexplained.
claimProject Blue Book was officially shut down in January 1970.
accountLeslie Kean was shown documents proving the existence of a government U.F.O. inquiry, which was the first such inquiry since the closure of Project Blue Book in 1970.
perspectiveJ. Allen Hynek argued that Project Blue Book's remit was to explain U.F.O.s away rather than to try to explain them.
measurementOf the ninety-one Project Blue Book cases selected for examination in the Condon Report, thirty remained official mysteries.
claimIn testimony before the House Armed Services Committee, J. Allen Hynek recommended the creation of an independent body to evaluate the merits of Project Blue Book.
claimJ. Allen Hynek argued that the remit of Project Blue Book was not to explain U.F.O.s, but to explain them away.
accountIn testimony before the House Armed Services Committee, J. Allen Hynek recommended the creation of an independent body to evaluate the merits of Project Blue Book.
accountThe United States government conducted an inquiry into U.F.O.s starting after the close of Project Blue Book in 1970, which was revealed to Leslie Kean through documents.
measurementOf the ninety-one Project Blue Book cases selected for examination in the Condon Report, thirty remained official mysteries.
measurementApproximately 95% of reported U.F.O. sightings investigated by Project Blue Book were attributed to common phenomena such as uncommon clouds, weather balloons, atmospheric temperature inversions, Venus, or classified military technology like the U-2 spy plane and the SR-71 Blackbird.
procedureLeslie Kean chose to focus her research on 'the really good cases' of UFO sightings that occurred after the closure of Project Blue Book, specifically those involving professional observers like pilots, multiple witnesses, and corroborating evidence like radar tracks or photos.
claimProject Blue Book was a U.S. Air Force program that operated out of Wright-Patterson Air Force Base near Dayton, Ohio, as a continuation of Project Sign.
claimJ. Allen Hynek, an Ohio State astronomer and former member of the Robertson panel, served as the only in-house scientist for Project Blue Book.
Unidentified flying object - Wikipedia en.wikipedia.org 18 facts
referenceA 1969 United States Air Force document known as the Bolender memo revealed that non-public U.S. government UFO investigations continued after 1970, stating that reports of unidentified flying objects that could affect national security were not part of the Blue Book system.
perspectiveJ. Allen Hynek, a trained astronomer and scientific advisor for Project Blue Book, was initially skeptical of UFO reports but eventually concluded that many sightings could not be satisfactorily explained.
accountEdward Ruppelt documented his experiences with Project Blue Book, a United States Air Force investigation into UFOs that occurred prior to the Condon Committee.
accountAstronomer and USAF consultant J. Allen Hynek and Captain Edward J. Ruppelt, the first head of Project Blue Book, revealed the existence of a suppressed top-secret intelligence estimate from Project Sign that had been ordered destroyed by Hoyt Vandenberg.
measurementThe USAF's Project Blue Book concluded that less than 2% of reported UFOs were 'psychological' or hoaxes, while a study conducted by Allan Hendry for the Center for UFO Studies (CUFOS) found that less than 1% were hoaxes or psychological in nature.
referenceEdward J. Ruppelt, the first head of the USAF Project Blue Book, authored 'The Report on Unidentified Flying Objects', published in 1956 by Doubleday & Company, Inc.
claimProject Grudge was a U.S. Air Force investigation that succeeded Project Sign in February 1949 and was subsequently succeeded by Project Blue Book in March 1952.
accountEdward J. Ruppelt, the head of Project Blue Book, described a 1952 CE2 case involving a patch of charred grass roots as a classic example of a UFO incident.
claimThe Robertson Panel was a scientific committee convened by the CIA and chaired by Howard P. Robertson that met in January 1953 to review the Project Blue Book report.
accountRemote radiation detection occurred over government nuclear installations at Los Alamos National Laboratory and Oak Ridge National Laboratory in 1950, as noted in FBI and CIA documents and reported by Project Blue Book director Edward J. Ruppelt.
measurementThe U.S. Air Force cataloged 12,618 UFO sightings between March 1952 and December 1969 as part of Project Blue Book.
claimGovernment-led UFO investigations, such as Project Blue Book in the United States and Project Condign in the United Kingdom, have occurred over the years without confirming the claims of ufologists who suggest UFOs are evidence of extraterrestrial intelligence, technologically advanced cryptids, interdimensional contact, or time travelers.
claimThe United States Air Force closed Project Blue Book in 1970, citing the Condon Committee's negative conclusion as the rationale for ending official Air Force UFO investigations.
quoteJ. Allen Hynek was highly critical of Project Blue Book, describing its operations as a "cavalier disregard by Project Blue Book of the principles of scientific investigation."
claimThe United States Air Force conducted Project Blue Book (which included the previous projects Project Sign and Project Grudge) from 1947 until 1969.
accountThe Air Force Director of Intelligence reorganized Project Grudge into Project Blue Book in late 1951, appointing Captain Edward J. Ruppelt to lead the project due to dissatisfaction with the quality of investigations conducted by Project Grudge.
referenceEdward J. Ruppelt wrote 'Project Blue Book and the UFO Story' in 1956.
claimEdward Ruppelt, a retired U.S. Air Force Captain and former director of Project Blue Book, published 'The Report on Unidentified Flying Objects' in 1956.
Steven M. Greer - Wikiquote en.wikiquote.org 3 facts
claimSteven Greer claims that Dr. J. Allen Hynek, the former head of the Air Force's Project Blue Book, described the amount of evidence regarding UFOs as an "embarrassment of riches."
claimDr. J. Allen Hynek, while in charge of Project Blue Book for the Air Force, described the evidence for UFOs as an "embarrassment of riches."
quoteSteven Greer quotes J. Allen Hynek, the former head of the Air Force's Project Blue Book, as describing the amount of evidence for UFOs as an 'embarrassment of riches.'
Ufology: From Fringe to Mainstream to Fringe? - Skeptic Magazine skeptic.com Feb 20, 2026 1 fact
accountThe U.S. Air Force terminated Project Blue Book, a program to study Unidentified Anomalous Phenomena, at the end of the 1960s.