The sentence that matters sits in paragraph four of a three-page typed memorandum. After discussing the matter with two colonels, the author records, “it was decided that the movies would be released without comment as to what they were and hope that no questions were asked about the Navy report.” The next line gives the decision its price: “This is a ‘calculated’ risk of another big ‘flap’.”
The memo is headed simply “Memorandum for Record.” Someone has pencilled “11 Feb 53” in the top corner, and it carries no signature. It sits on PDF pages 37 to 39 of the Project Blue Book file on the Tremonton film (DOW-UAP-D102), which the Department of War published on September 18, 2026 as part of the sixth PURSUE release. Scanned out of order (it runs 37, 39, 38), it is the clearest record yet released of the Air Force working out what it would say in public about a case it had not solved, and the officers were unusually frank on paper about why.
A film, two labs and a promise
On July 2, 1952, the Navy photographer Delbert C. Newhouse (the February 1953 teleconference first calls him a Chief Petty Officer, then records his correction: Chief Photographer, a commissioned warrant officer), driving through northern Utah with his wife, stopped on the highway north of Tremonton and filmed a loose group of bright objects with a handheld Bell & Howell Auto Master. The film went to two laboratories: the Air Force’s Photo Reconnaissance Laboratory at Wright-Patterson and the Navy’s Photographic Interpretation Center in Washington. His final Navy personnel record, released in the same tranche, confirms a career behind cameras; the case history covers the sighting in full.
The press problem arrived on January 29, 1953. According to the memo’s first paragraph, Captain Edward Ruppelt, head of Project Blue Book, was in Washington that day and learned that “the press had learned about the Tremonton, Utah, movies.” Al Chop of the Department of Defense’s Office of Public Information, Colonel Teaberg of the Air Force intelligence directorate and others wanted the film released “in accordance with the promise made this summer to the press that no information on the subject of Unidentified Flying Objects would be withheld.” Ruppelt agreed. The plan was for the facts to go to Captain Harry B. Smith at AFOIN-2A2, who would pass them to Chop, who would write the release (p. 37).
The file preserves Ruppelt’s side of that exchange. A teleconference message dated February 3, 1953, from Ruppelt to Smith, carries the “data for press release on Tremonton movies” (PDF pages 78 and 80). It reports that attempts to trace leftover pillow balloons to the Tremonton area were negative, and calls seabirds “another strong possibility.” It says movies of gulls taken under similar lighting showed them “appearing as bright spots of light very similar to those in the movies,” and closes: “At the present time the Air Force contemplates no future action will be taken to identify the objects.” On February 10 Smith wired back two short sentences: “Release of Tremonton films still being studied here. Will forward next telecon” (p. 40).
What the officers were afraid of
By February 9, Chop had written his release and shown it to Colonel Smith of AFOIN-2A. Both men could see the next question coming. Reporters would ask what the Air Force and Navy photo labs had found, “and that these reports would have to be released. If they weren’t released, the press would begin to think they contained some ‘hot’ material and that the Air Force was holding back some important data.” ATIC, the Air Technical Intelligence Center that housed Blue Book, “concurred that this could happen, and that if it did happen it could create a great deal of excitement” (p. 37).
The difficulty was that neither lab report said what the February 3 teleconference said. The memo summarises the Air Force laboratory first. Its analysts were “reasonably certain that the brightness of the images on the film exceeds that of any bird.” The objects “are not spherical,” and on the original page the word “balloons” after that phrase has been struck through by hand. A third finding, that the objects could be aircraft, has its item letter struck through; the typed note that follows argues that “the absence of sound almost rules out aircraft,” and someone has circled that note in red and written “not so!!!” in the margin beside it (p. 37).
The Navy’s findings went further. The memo lists them as “Self-luminous or light sources,” “Could not be aircraft or balloons,” and a third item stating that no bird was known to reflect enough light to produce the images on the film. The Navy analysts had reached this from measuring “the brightness of the image on each frame,” work that “required about a 1,000 manhours.” Then comes the qualification that the rest of the memo leans on: “It was brought out by two astronomers who heard a Navy briefing on the analysis of the movies that the method used to measure the brightness of each spot was wrong, therefore, the results of the entire study were wrong” (p. 39). A reader has footnoted the word “brightness” by hand with a note, only partly legible in the scan, that it depends on shutter opening, exposure and the position of the sun.
So the Air Force had two formal laboratory analyses. Both, on brightness, pointed away from birds. The Navy’s had been challenged on method by two astronomers, and parts of the memo’s summary of the Air Force findings had been struck through by hand. Meanwhile the explanation Blue Book was preparing to give the public was gulls or balloons.
The plan
Paragraph four records the choice made with Lieutenant Colonel Johnston and Colonel McDuffy: release the film without saying what it showed, and hope nobody asked about the Navy. Paragraph five sets out “the other alternative,” which was “to quickly get more data.” It lists four steps in the order they could be done. The first was to film gulls in bright sun with a three-inch lens at known distances, because “the big question is, how much light will be reflected? Can you see a gull reflecting light and not recognize that it is a gull?” In February, the memo notes, “Florida is the only place where sunshine and gulls can be assured.” The second was to use special funds to have General Mills release pillow balloons in the same arrangement as the objects on the film. The third was to have two aircraft manoeuvre at different altitudes and photograph them. The fourth was to “Request that the Navy re-do the study using the methods of density measurement that are prescribed by the astronomers” (pp. 39, 38).
The pillow balloons had a paper trail of their own. In December 1952 Lieutenant A.G. Flues of ATIC contacted General Mills in Minneapolis, believed to be the balloons’ only maker, which said large numbers had gone to the “Crusade for Freedom” and been released for publicity around the country (two memos disagree on whether that was the winter of 1951 or 1952). At a screening in the University of Minnesota’s balloon room on December 30, the consensus of the balloon specialists present was that the objects “resembled pillow balloons in flight very closely.” General Mills’ J.R. Smith was the least convinced, feeling the objects were “a bit too bright” and “maneuvered a bit too fast” (PDF pages 26 to 29). The file records no release traced to the Tremonton area; the February 3 teleconference calls those attempts negative.
Then the memo’s Conclusion, at paragraph six. “If it is deemed advisable to release the movies quickly, state that the Air Force cannot positively identify the objects but they are reasonably sure that they are balloons or gulls consequently no further effort is going to be put into the incident. If the Navy and Air Force reports are requested, state that due to the meager data they used, the reports must be discounted.” The paragraph ends with a sentence someone later underlined in red: “It would be rather poor policy to state that the Navy had made an error in the beginning of their analysis.” If even that was too risky, paragraph seven says, the first three data-gathering steps should go ahead “on a high priority basis.” The fourth, asking the Navy to redo its study, is left off that list. The recommendation was to hand the plan to AFOIN-2A2 to take to the Director of Intelligence (p. 38).
Reading it fairly
It would be easy to call this a cover-up, and the memo does not support that. Nothing in it conceals a finding the author believed was true. He thought the Navy’s measurements were unsound, and he said so on paper. The public line he drafted opens with an accurate admission, that the Air Force “cannot positively identify the objects.” The “meager data” complaint was fair too: the film had no reference points, and every later reviewer has hit the same wall.
Its weaknesses lie elsewhere. The suggested wording claimed more confidence in balloons or gulls than the Air Force’s own laboratory had given it, and it proposed announcing that no further effort would be made while listing, a paragraph earlier, the experiments that would be needed to settle the question. It also let interservice courtesy decide what the public would be told: the Navy’s analysis was to be “discounted” on grounds of meagre data instead of the specific methodological objection the author actually held, because naming the error would be “poor policy.” And the one step that would have tested that objection directly, a Navy re-run using the astronomers’ method, was the step dropped from the high-priority list.
The two astronomers are not named. The best-documented Navy briefing on the film that winter was the one given to the scientific panel the CIA convened under the physicist H.P. Robertson, which met in the middle of January 1953, a few weeks before this memo. The panel viewed the Tremonton film and the 1950 Great Falls footage, and heard the Navy analysts present their work. Its members included the astrophysicist Thornton Page, and J. Allen Hynek, the Ohio State astronomer who consulted for Blue Book, attended as an associate member. Page asked to see a film of gulls; the panel concluded that the Tremonton objects were most probably birds. That may account for the gull footage Ruppelt cited on February 3. Identifying Page and Hynek as the two in question is plausible and remains unconfirmed.
Where the story went
The file’s later assessments followed the course the memo anticipated. The Air Force drifted from pillow balloons toward seabirds soaring on thermals, and the service’s line on Tremonton settled there. The footage reached cinemas in the 1956 documentary Unidentified Flying Objects, made with Chop and Ruppelt’s cooperation, and the case entered the literature in the form it has kept since: the film the Navy proved was not birds.
That version rests on the Navy analysis as it was briefed in 1953, and the documents now public complicate it from both ends. The Navy’s own film analysis memorandum (DOW-UAP-D098), published in the fifth release, is more guarded than the legend. Its analysts write that they could not explain the objects under the conditions of the photography and could not recognise them as man-made, and they note that the investigation was limited and that no attempt was made to corroborate the opinions presented. The February 1953 memo adds that the brightness method underpinning those conclusions was disputed by astronomers within weeks, and that the Air Force’s own lab had independently leaned against birds on brightness. The companion photo file holds the balloon review.
Seventy-three years on, page 39 still carries the question the officers could not yet answer, typed a few lines below their decision to hope nobody asked: “Can you see a gull reflecting light and not recognize that it is a gull?”
Sources
- DOW-UAP-D102, Project Blue Book File on Tremonton Film, Utah, 1952 (war.gov PDF): memorandum for record, PDF pages 37 to 39; teleconferences of February 3 and 10, 1953, PDF pages 40, 78 and 80; pillow-balloon inquiry, PDF pages 26 to 29
- Tremonton Utah UFO Film: case history