THE DOCUMENT
DOE-UAP-D004, “Los Alamos Conference on Aerial Phenomena, 1949”, a written record from the U.S. Department of War’s PURSUE Release 04, published at war.gov/ufo, cleared 10 July 2026. It is a transcript of the minutes of a conference held at 1300 on 16 February 1949, in conference room P-162 at Los Alamos Scientific Laboratory, New Mexico, on the “green fireballs” reported around the laboratory over the preceding months, transmitted to Sandia Base under a U.S. Atomic Energy Commission letter of 22 March 1949, the date the release database uses. Release 04 is the first PURSUE tranche to include Department of Energy records, and D004 is the earliest of them.
Why this one is worth your time
Release 02 gave this series the Sandia file, a 116-page log of sightings around a nuclear weapons base between 1948 and 1950. Release 04 now supplies the other half of the New Mexico story: the meeting where the scientists tried to explain it. On a February afternoon in 1949, the people in a Los Alamos conference room included Edward Teller, Frederick Reines and the laboratory’s director, alongside the region’s meteor specialist, an FBI agent and Army officers, and the subject on the table was what had been crossing the sky over the laboratory for two months. The minutes run twenty-four pages, record a physicist and a meteor expert testing each other’s readings in real time, and end without an answer. This briefing sets out who was in the room, what the transcript records them trying, and how it closes.
What the document says
The paperwork and the room. The file opens with a covering letter from the Atomic Energy Commission’s Santa Fe operations office, reference SFD-3-1, dated 22 March 1949 and signed by Sidney Newburger, Jr., Chief, Security Operations Branch, furnishing a transcript of the conference minutes to Lieutenant Commander Richard Mandelkorn at Armed Forces Special Weapons Project headquarters, Sandia Base. The minutes themselves are headed “Conference on Aerial Phenomena”, stamped as copy 18 of 25, with SECRET markings struck through in declassification. The attendance list records the Fourth Army (Major Winn, Major Godsoe, Captain Neef), AFSWP (Commander Mandelkorn), the University of New Mexico (Dr. LaPaz), the FBI (Mr. Maxwell), the AEC’s Santa Fe Operations Office (Mr. Morgan, Mr. Newburger) and the University of California, the laboratory’s operator (Dr. Bradbury, Dr. Holloway, Mr. Hoyt, Dr. Manley, Dr. Reines, Dr. Teller); the release’s catalogue note describes the gathering as including several eminent physicists, many of them Manhattan Project veterans, convened to discuss and gather hypotheses on the phenomenon’s nature and origin. Newburger opens by stating that the subject is classified Secret and everyone present is cleared. Captain Neef then outlines the purpose: the reports began in December 1948, first from airline pilots, and Dr. LaPaz had been assisting the investigation, unpaid, since then.
LaPaz’s case that these were not meteor falls. The transcript records LaPaz building a baseline first: what a conventional meteorite fall looks like, steep, randomly oriented, attended by sound. Against it he sets the fireballs, beginning with the one he witnessed himself, the Starvation Peak incident of 12 December 1948, timed at 9:02 P.M. plus or minus 30 seconds, with transit measurements taken within two or three minutes of the event. He describes a fireball that appeared at full intensity instantly, a green or yellow-green he estimates near wavelength 5,200 angstroms, such as he had never observed in meteor falls, a path as nearly horizontal as visual observation could determine, and a duration of about two seconds before it broke into fragments, still bright green. For the class as a whole he records durations clustering near that figure, paths horizontal or nearly so at elevations of the order of 8 to 10 miles, held at nearly constant velocity, and he says he defies anyone to find conventional meteorites that behave that way. Only three real paths, he notes, had been determinable: 12 December, 20 December and the very large fall of 30 January 1949. His stated view is that the December 12 fireball was not, in his opinion, a conventional meteor fall, and that since most reported green fireballs share its properties, in all probability neither are they.
The physicists’ tests. The discussion the transcript preserves is a series of checks. Sound is the recurring one: Teller and Mandelkorn work through whether a solid object at 8 to 10 miles could pass overhead inaudibly, Holloway asks what sound a V-2 makes, and LaPaz answers that his group tried desperately to obtain confirming evidence whenever sounds were mentioned, and no reports were obtained. The minutes then note that Teller spent approximately the next twenty minutes figuring on the blackboard, estimating light, speed, kinetic energy and shock wave. His position after it, as the transcript records: if he can believe everything he has heard and put it together with what he theoretically believes, it ought to be a material body, and might be an electron phenomenon. LaPaz replies that this is exactly why he is puzzled: nothing like this, to his knowledge, has ever been observed in the case of meteorite drops. Teller suggests a good sound laboratory could turn the absence of sound into an upper bound on the object’s size, something like a cubic centimetre, which he says would not have given the blinding effect if it was a material object; Bradbury answers that light effects need not come from kinetic energy at all, since light can come from chemicals as well.
How it ends. Newburger observes that this seems to wind up the meeting. The last words in the minutes belong to Bradbury: he still does not feel that the meteor explanation is out, and what puzzles him is the long horizontal path, and the absence of noise. No consensus, no attribution and no recommendation is recorded; the catalogue note reads the file the same way, recording that the group did not reach agreement on a likely attribution, with meteors entering the atmosphere at a shallow angle and high altitude the leading hypothesis on the table.
What the transcript preserves about its own making. The stenographic record keeps its own gaps visible. One parenthesis notes that a minute or two of LaPaz’s comments were drowned out by noise from a ditch digger immediately outside the conference room; others mark talk between Bradbury and LaPaz as too fast and too jumbled to be transcribed, or simply too much cross talk; elsewhere the text trails into ellipses where words were lost. The minutes end with the typist’s initials.
What the document does not say
It records no finding. The meeting ends on a standing disagreement, with the meteor hypothesis neither adopted nor excluded, and the transcript assigns the fireballs no cause.
It is a record of talk, not an investigation file. The complete AESS reports LaPaz says he brought and offered to circulate, the photograph he mentions, and the observational data behind the December and January falls are referred to in the discussion but not bound into the released file.
It does not entertain the reading a modern reader might expect. No speaker in the released pages describes the fireballs as craft; the alternatives weighed in the room run between unusual meteoric behaviour and other natural or physical effects.
It does not mention Project Twinkle or any follow-on programme. The instrumented watch the Air Force stood up later in 1949 is context from the wider record, not from this file.
Its text layer is uneven. The released scan is a violet typescript whose machine-extracted text corrupts many passages, including the meeting’s two best-known lines, which are summarised above rather than quoted; the quotations below are limited to fragments that survive byte-identically.
From the record
Conference on AERIAL PHENOMENA DOE-UAP-D004, the heading and running header of the minutes
The green fireballs are unusual in this respect: DOE-UAP-D004, Dr. LaPaz, introducing what the transcript goes on to record as their nearly horizontal, low, constant-velocity paths
the long horizontal path; also, absence of noise is puzzling. DOE-UAP-D004, Dr. Bradbury, the transcript’s closing line (the sentence opens, in the scan-damaged text, with his statement that he still does not feel the meteor explanation is out)
Where the case connects
Readers of the Sandia briefing will recognise the geography and the dates. Release 02 Briefing 3 covers DOW-UAP-D017, the 116-page log of 209 sightings around Sandia Base from 1948 to 1950: that file records the observations, this one records the attempt to explain them, and the released paper makes the connection documentary rather than thematic, since the transcript travels under an AEC letter addressed to Commander Mandelkorn at AFSWP headquarters, Sandia Base, the same organisation whose sighting log Release 02 published. The two files were released under the same programme two months apart, and they read as two chapters of one episode. The same winter produced the Air Force’s assessment layer: Release 04 Briefing 1 covers Study No. 203, dated ten weeks before this conference, whose summary sorts the era’s reports into disks, cigar shapes and balls of fire. Four years later the fireball problem reached a different table: the Robertson Panel file of Release 03 Briefing 6 lists a report on the New Mexico green fireball phenomena, Project TWINKLE, among the evidence put before the CIA’s 1953 panel. And the tranche’s other Department of Energy record, the Pantex report of Release 04 Briefing 7, extends the nuclear-sites thread to 2015. That thread, why so many early reports concentrate around atomic installations, has run through this series since the Sandia briefing; D004 does not answer it, and the conference itself could not.
The file also leaves its own loose ends. The AESS reports and the photograph LaPaz cites, the path determinations for the December and January falls, and any record of what Sandia did with the transmitted minutes are all outside this file. Any later tranche that releases the underlying observation reports, the Twinkle records or a cleaner scan lands in this series when it does.
Read it yourself
DOE-UAP-D004, “Los Alamos Conference on Aerial Phenomena, 1949”, is hosted at war.gov in PURSUE Release 04.
Read the file. Decide for yourself.
Related wiki entries
The wiki entries below give background on the programme and publisher behind this briefing, and on the subjects it touches.
- PURSUE
- Department of War
- Los Alamos Conference on Aerial Phenomena
- Lincoln LaPaz
- Edward Teller
- Green Fireballs
References and further reading
- DOE-UAP-D004, “Los Alamos Conference on Aerial Phenomena, 1949”, PURSUE Release 04, U.S. Department of War, hosted at war.gov/ufo
- Presidential Unsealing and Reporting System for UAP Encounters (PURSUE), U.S. Department of War, war.gov/ufo
- AARO UAP Records, All-domain Anomaly Resolution Office, aaro.mil/UAP-Records
- Signals from the Periphery, Release 02 Briefing 3, on the green fireballs of the Sandia file
- Signals from the Periphery, Release 04 Briefing 1, on Air Intelligence Division Study No. 203
- Signals from the Periphery, Release 04 Briefing 7, on the Pantex report of 2015
- Signals from the Periphery, Release 03 Briefing 6, on the Robertson Panel