Government and military
The Air Force UFO studies from 1947 to 1969: Sign, Grudge, Blue Book and the Condon study. 116 events, newest first.
Select any year above to see what happened that year.
Open Project Blue Book as a timeline
Media19 Jul 2019
History launched The UnXplained, a nonfiction series on unexplained mysteries hosted by William Shatner and produced by Kevin Burns of Ancient Aliens. It joined a Friday block that included Unidentified and Project Blue Book.
Photo: Super Festivals from Ft. Lauderdale, USA, CC BY 2.0
Media8 Jan 2019
History premiered a period drama from executive producer Robert Zemeckis, starring Aidan Gillen as astronomer J. Allen Hynek, with episodes drawn from Air Force Blue Book cases. It ran two seasons before History ended it in 2020.
Photo: U.S. Air Force, Public domain
Media20 Jan 2015
John Greenewald's site The Black Vault posted about 129,500 pages of Air Force Project Sign, Grudge and Blue Book records as searchable PDFs. The files had long been viewable on microfilm at the National Archives but had not been fully online.
GovernmentJun 1995
USAF Fact Sheet 95-03 set out the Air Force's standing answer on UFOs: Blue Book logged 12,618 sightings, 701 stayed unidentified, none showed a threat or evidence of extraterrestrial craft, and nothing since 1969 justified resuming investigations. Af.mil still carries the text.
Photo: U.S. Air Force, Public domain
Government1987
Stanford astrophysicist Peter Sturrock published a review of the Air Force-funded Condon Report in the first issue of the Journal of Scientific Exploration. He argued the director's summary differed substantially from the staff's case findings, which stressed unanswered questions.
Close encounters27 Apr 1986
Astronomer J. Allen Hynek, longtime scientific consultant to the Air Force UFO projects, died at 75 in Scottsdale, Arizona. He had become a critic of Blue Book's methods, founded the Center for UFO Studies and coined the 'close encounters' terms in his 1972 book.
Photo: United States Government, Public domain
Media19 Feb 1978
NBC premiered Project U.F.O., a Jack Webb series in which Air Force investigators looked into sightings. Webb drew episode ideas from Project Blue Book files; the show ran until July 1979.
Photo: Photographer not credited, Public domain
GovernmentDec 1977
On July 21, 1977, Frank Press, science adviser to President Carter, wrote to NASA Administrator Robert Frosch proposing a panel to check for significant new UFO findings since the Condon Report. About five months later NASA answered that neither a research effort nor a symposium was justified.
Photo: NASA, Public domain
Media1977
J. Allen Hynek, the Air Force's longtime scientific consultant on Project Blue Book, published The Hynek UFO Report, drawing on Blue Book material to criticize how the Air Force handled UFO reports. MUFON reissued it in 2020.
Photo: United States Government, Public domain
Government1976
The Air Force placed its Project Blue Book UFO files in National Archives custody in 1975. After witness names were redacted, the records opened to public research in spring 1976 and are read today on 94 rolls of microfilm (T-1206).
Photo: Steve Jurvetson, CC BY 2.0
Media1975
Former Blue Book consultant J. Allen Hynek and computer scientist Jacques Vallee published 'The Edge of Reality: A Progress Report on Unidentified Flying Objects', treating UFOs as a real but unexplained phenomenon and proposing a framework for further study.
Photo: United States Government, Public domain
Government26 Mar 1974
Physicist Edward U. Condon, a Manhattan Project veteran who was investigated by the House Un-American Activities Committee in 1947-1949, died in Boulder, Colorado.
Photo: National Institute of Standards and Technology, Public domain
Government1974
Lt. Col. Hector Quintanilla Jr., a former chief of Project Blue Book, wrote a book proposal titled 'UFOs: An Air Force Dilemma', dated 1974. A scan of the typescript, described as his proposal for a book, is publicly available online.
Photo: U.S. Air Force, Public domain
Close encounters1973
Astronomer J. Allen Hynek, former scientific consultant to Project Blue Book, started the Center for UFO Studies, initially run from a room in his Evanston home. He led it as scientific director until his death in 1986; it continues as a research library and archive.
Photo: United States Government, Public domain
Media1973
Donald Keyhoe, a longtime critic of Air Force UFO secrecy, published 'Aliens from Space: The Real Story of Unidentified Flying Objects', restating his long-held case that the Air Force withheld UFO evidence, after Project Blue Book had closed.
Photo: CBS, "The Mike Wallace Interview" 1958 March 8, Public domain
Government17 Dec 1969
Air Force Secretary Robert Seamans Jr. announced the end of Project Blue Book, citing the Condon study and its review by the National Academy of Sciences. The Air Force said no case it had studied showed a threat to national security or evidence of extraterrestrial vehicles.
Photo: United States Air Force Archive, CC BY-SA 4.0
Government20 Oct 1969
Brig. Gen. C. H. Bolender, Air Force deputy director of development, recommended ending Project Blue Book. It noted that UFO reports that could affect national security went through standard military channels and were not part of the Blue Book system. Researchers disagree on what that implies.
MediaApr 1969
In a review essay titled 'The Condon Report and UFOs', Blue Book science consultant J. Allen Hynek argued that the report's own unexplained cases did not support its conclusion that further UFO study was not worthwhile, and faulted its case selection and methods.
Photo: Bulletin of the Atomic Scientists, Public domain
Government1969
An Air Force-funded University of Colorado study led by physicist Edward Condon was made public. It concluded that further UFO study was unlikely to advance science, and the Air Force later cited it when closing Project Blue Book.
Photo: National Institute of Standards and Technology, Public domain
GovernmentJan 1969
An Air Force-requested National Academy of Sciences panel chaired by Gerald Clemence reviewed the University of Colorado UFO study and judged its scope and methods sound, agreeing that further UFO study deserved no high priority. The Air Force cited this review when it closed Project Blue Book.
Photo: G. Edward Johnson, CC BY 4.0
GovernmentJan 1969
A chapter of the Air Force-funded Condon report, by astronomer Franklin Roach, reviewed what Mercury and Gemini crews saw in orbit. It found most sightings explainable but judged three unexplained: two by James McDivitt on Gemini 4 and one by Frank Borman on Gemini 7.
Photo: National Institute of Standards and Technology, Public domain
Close encounters1969
After a stormy board meeting, Donald Keyhoe gave up the directorship of NICAP and moved to its board; accounts cite money troubles. Jack Acuff took over as the civilian group declined in the years after the Air Force closed Project Blue Book.
Photo: CBS, "The Mike Wallace Interview" 1958 March 8, Public domain
GovernmentJan 1969
The Air Force-funded Condon Report included the 1956 Lakenheath-Bentwaters radar-visual case as its Case 2. The study said it learned of the case in winter 1968 from an unsolicited letter by the retired USAF watch supervisor on duty that night, and obtained the Blue Book file afterward.
Photo: Chris, CC BY-SA 2.0
Military24 Oct 1968
Missile-site maintenance and security crews near Minot AFB reported a glowing object for over three hours, and a returning B-52 crew tracked a target on radar that paced the bomber while its radios failed to transmit. Project Blue Book attributed the reports to a natural phenomenon.
Photo: Project Blue Book, Public domain
Media14 May 1968
John G. Fuller's Look article described turmoil in the Air Force-funded Colorado UFO study, quoting a 1966 memo by coordinator Robert Low that spoke of a 'trick' to make the project look objective. Condon called the article false and misleading; two dismissed staff members were central to the story.
Photo: National Institute of Standards and Technology, Public domain
