The 1949 Los Alamos Conference on Aerial Phenomena: Teller, LaPaz, and the Green Fireball Enigma

Source file: DOE-UAP-D004_Los-Alamos-Conference-on-Aerial-Phenomena_1949.pdf Originating agency: U.S. Atomic Energy Commission (USAEC), Santa Fe Directed Operations / Los Alamos Scientific Laboratory (now under the Department of Energy) Document type: Conference transcript with transmittal letter Date: February 16, 1949 (conference); March 22, 1949 (transmittal letter) Classification: SECRET (declassified; authority NND 58378, NARA, June 2026) Page count: 25 (all read): transmittal letter + a 24-page numbered transcript VIRIN: 260710-O-D0360-1132 PURSUE Release: 4

Summary

This document is the full transcript of a "Conference on Aerial Phenomena" held at 1300 hours on February 16, 1949, in conference room P-162 of the Los Alamos Scientific Laboratory, New Mexico. The subject: the wave of "green fireball" sightings over New Mexico that had begun, as Captain Neef explains in his opening remarks, in December 1948 with reports from airline pilots. Around the table sat some of the Manhattan Project's most senior scientists, including Edward Teller, laboratory director Norris Bradbury, Fred Reines, and John Manley, alongside Dr. Lincoln LaPaz, the University of New Mexico meteor expert leading the field investigation, and officers of the Fourth Army, AFSWP, the FBI, and the Atomic Energy Commission.

LaPaz presents the physicists with the data he has gathered: almost perfectly horizontal paths at 8 to 10 miles altitude, velocities of 3 to 12 miles per second, a yellow-green hue near 5,218 angstroms ("about the color you get when you have copper salts in the Bunsen burner"), unusually uniform duration estimates, a total absence of sound, and a total absence of fragments on the ground despite extensive searches. His conclusion: these are not conventional meteors. Teller, after roughly twenty minutes of blackboard work estimating light, speed, and kinetic energy, arrives at a two-sided bottom line: it "ought to be a material body - might be an electron phenomenon." The conference ends without resolution, with Bradbury observing that "the meteor stuff" is not ruled out, but "the puzzling thing is the long horizontal path; also, absence of noise is puzzling." The transcript was forwarded on March 22, 1949, to Lt. Cmdr. Richard Mandelkorn at AFSWP Headquarters, Sandia Base.

Research Article

The Document and Its Path

The package opens with an official Atomic Energy Commission transmittal letter from Los Alamos, dated March 22, 1949, signed by Sidney Newburger, Jr., Chief of the Security Operations Branch, addressed to Lt. Cmdr. Richard Mandelkorn at Armed Forces Special Weapons Project (AFSWP) Headquarters, Sandia Base, Albuquerque: "Furnished herewith is a transcript of the minutes of the conference held at Los Alamos February 16, 1949, pertaining to aerial phenomena." The sheet is stamped "SECRET TRANSMITTAL" (struck through upon declassification), and the transcript itself, copy 18 of 25 in Series A, carries SECRET markings on every page. Newburger opened the conference by stating that the subject was classified Secret within the meaning of regulation AR 380-5.

The attendance list is a rare cross-section of the 1949 national-security scientific establishment: from the Fourth Army, Major Winn, Major Godsoe, and Captain Neef; from AFSWP, Commander Mandelkorn; from the University of New Mexico, Dr. LaPaz; from the FBI, Mr. Maxwell; from the Atomic Energy Commission (USAEC, SFOO), Mr. Morgan and Mr. Newburger; and for the University of California (operator of Los Alamos), Dr. Bradbury, Dr. Holloway, Mr. Hoyt, Dr. Manley, Dr. Reines, and Dr. Teller.

One limitation of the source itself should be noted: the stenographer records at several points that the recording went blank ("record blank for short period"), that exchanges were "too fast and too jumbled to be transcribed," and that noise from a ditch digger just outside the conference room drowned out portions of the discussion. A few names appear in the transcript with question marks or in garbled spellings.

LaPaz's Presentation: Why These Are Not Meteors

LaPaz, who had been assisting the investigators "gratis" since December 1948, built his argument on a systematic comparison with conventional meteorite falls. His central witness is himself: on the night of December 12, 1948, at 9:02 P.M. (plus or minus 30 seconds), he observed a green fireball near Starvation Peak while equipped with a stopwatch and a surveyor's transit. The fireball "appeared in full intensity instantly," in a green or yellow-green hue estimated around 5,200 angstroms, "such as I had never observed in meteor falls before," moved along a nearly perfect horizontal path at constant angular velocity, and finally broke into fragments "still bright green." Duration of the observation: almost exactly two seconds.

From there LaPaz laid out the statistics: whereas 100 ordinary meteor observations produce enormous scatter in duration estimates, some 90 percent of the duration determinations for the green fireballs cluster around the same value. Three cases allowed determination of a real path (December 12, December 20, and January 30, 1949), and all indicate horizontal trajectories at elevations of 8 to 10 miles. "I defy you to find anywhere among meteorists, examples of conventional meteorites that move over long horizontal paths reserving nearly constant angular velocities... at elevations of the order of 8 to 10 miles," he said. In color tests using a spectrum chart, 90 percent of witnesses chose wavelengths between 4,900 and 5,300 angstroms, most falling close to 5,218, the color of copper salts; LaPaz even consulted Dr. Regener on whether a copper-beryllium alloy would alter the hue. A check of 414 Geminid shower observations since 1915 turned up not a single green one.

Two anomalies troubled LaPaz above all. First, the absence of sound: the January 30, 1949, fireball produced light visible at distances of the order of 400 miles, yet an investigation pursued over 1,600 miles ("in Texas mud primarily!") and hundreds of interviews over some ten days yielded "not one substantiated account of noise." The single exception: a group of five men near a steel smokestack at Roswell, every one of whom swore they heard a noise "like, say, a gasoline blowtorch" while watching the green fireball go by. Second, the absence of fragments and of animal alarm: in every meteorite fall he had investigated, chickens, dogs, and horses panicked; here, nothing. Even the Four Corners fall of October 30, 1947, investigated with an exhaustive ground and air search (CAP aircraft, radio-controlled jeeps), yielded "not a trace," though LaPaz declined to classify it with the green fireballs because it left a train.

In all, LaPaz testified to ten incidents "that definitely merit the most serious consideration," strictly analogous to the December 12 observation, plus roughly twenty more with deviations. The phenomenon concentrated in New Mexico; similar reports had come from the Hanford area (via a Dr. Pruitt) and from near Las Vegas, New Mexico, where, as noted at the conference with some interest, there is also a place called Los Alamos.

The Debate: Material Body or "Electron Phenomenon"

Teller conducted the cross-examination: Was the intensity constant? How long did the phenomenon last? What is the computed velocity? (3 to 12 miles per second, probably around 10, based on a path of over 100 miles covered in 5 to 14 seconds in the January 30 fall.) LaPaz framed the paradox: "unless you feed power into a body moving into a horizontal path, can it preserve essentially a horizontal trajectory? A plane does it; meteorites don't do it... This thing apparently ignores air resistance and gravity and goes blissfully on its way."

Near the end of the session, the transcript notes, "Dr. Teller then spent approximately the next twenty minutes or so figuring on the blackboard - estimating light, speed, kinetic energy, shock wave, etc." His conclusion: a solid object crossing the atmosphere horizontally at 8 to 10 miles altitude must produce an audible shock wave, unless it is tiny, "as small as an inch or smaller"; yet a one-centimeter object "would not have given the blinding effect, if it was a material object." Hence his alternative suggestion, an "electron phenomenon," that is, an electrical-atmospheric effect rather than a solid object. Mandelkorn sharpened the point: "From what Dr. Teller said apparently a solid object converging with the atmosphere horizontally at about 8 to 10 miles altitude, it's incredible that it wouldn't be accompanied by some sort of sonic phenomenon." Bradbury noted that light can also be produced chemically, without kinetic energy, and closed with characteristic caution: the meteor is not ruled out, but the long horizontal path and the absence of noise are puzzling.

Also noteworthy is LaPaz's own hypothesis, offered with open hesitation: "I think these are defensive manoeuvers of some higher U.S. Command and they are practising in the neighborhood of the regions they are going to defend, so naturally your localization of light near the atomic bomb installations, but boy, am I scolded for that!" Even Dr. Kaplan, he said, assured him the relevant authorities "don't have any facts." Later exchanges also ruled out German experiments or prior European knowledge, and LaPaz remarked that meteoritics was more highly developed in the Soviet Union than anywhere else, with full state support, and that at an international meeting the Soviets had moved to block an international committee to investigate the meteorite crater of February 1947.

The Institutional Backdrop: From "Crackpots" to Project Grudge

The transcript captures the institutional moment at which the Los Alamos problem connected to the Air Force's national UFO program. When Newburger asked whether the national defense establishment had contributed anything, Major Godsoe answered: "No, most of the military authorities think we are crackpots; that is, except for the Army Air Force, which is taking an active interest in details," and stated the meeting's purpose with disarming candor: "we want you to find a meteor!" Newburger raised the matter of the "flying discs" because the Air Force, as he understood it, had now classed the discs and the fireballs "into one category," and Captain Neef confirmed: according to a letter from the Air Materiel Command in Washington, "the old project Sign is now project Grudge, which includes the phenomena observed in New Mexico. They knew of this meeting and were going to send a representative."

The conference also discussed documentation efforts: a photographic patrol posted on the night of December 19, 1948 (in which Mr. Maxwell of the FBI participated) missed the phenomenon, and the photographic meteor station Harvard College had installed near or inside the White Sands Proving Ground, under a Navy contract, had produced no determinations owing to "red-tape channelization impedimenta." Harvard's expensive "meteorschmitt" cameras and a Cornell photoelectric trigger design were mentioned. A letter read aloud from a General Bunker described General Carroll's impression of a spectacular northern-lights display at Fairbanks, Alaska, and concluded: "So far as we know, it is still phenomena and not material."

Connections in the Collection: DOW-UAP-D017 and DOE-UAP-D002

This transcript is the central companion document to the Sandia Base green fireball file (DOW-UAP-D017, PURSUE Release 2), the 116-page package documenting the OSI, AEC, and Fourth Army investigation of 1948-1950, including LaPaz's serial reports and the master table of hundreds of sightings. The cast is identical: Mandelkorn (addressee of the transmittal letter here, and author of summaries in the Sandia file), Major Godsoe, LaPaz, the AESS, and the OSI (the transcript mentions a Lt. Ryan "of the Roswell group of the OSI," who investigated sound reports). Where the Sandia file preserves the administrative record of that investigation, here the conference room itself can be heard, word for word. The James Tuck correspondence (DOE-UAP-D002, Release 2), with its recollection of green lights over Los Alamos in 1948-1951, belongs to precisely the same historical setting.

Significance

This is one of the strongest historical documents in the entire PURSUE collection: a verbatim record in which the senior physicists of the American nuclear weapons program, including the director of Los Alamos himself, spend hours confronting an unidentified aerial phenomenon over the nation's most sensitive nuclear installation, subject it to quantitative physics, and fail to reconcile it with any conventional explanation. The document also records, in real time, the transition of Project Sign into Project Grudge and the joint categorization of the "discs" and the fireballs, and it exemplifies the recurring pattern in the collection: anomalous aerial activity concentrating around nuclear weapons sites, investigated with utmost seriousness far from public view. That the group, in the official release blurb's phrasing, "did not come to a consensus on a likely attribution" is itself the finding.

Key People

Locations

Incidents

Notable Quotes

"If I can just believe everything I have heard and put it together with what I theoretically believe in, it ought to be a material body - might be an electron phenomenon." -- Dr. Teller, p. 24

"You see why I'm puzzled, Dr. Teller. Nothing like this, to my knowledge, has ever been observed in the case of meteorite drops." -- Dr. LaPaz, p. 24

"This thing apparently ignores air resistance and gravity and goes blissfully on its way." -- Dr. LaPaz, p. 16

"No, most of the military authorities think we are crackpots; that is, except for the Army Air Force, which is taking an active interest in details." -- Major Godsoe, p. 15

"Still don't feel that the meteor stuff is out. The puzzling thing is the long horizontal path; also, absence of noise is puzzling." -- Dr. Bradbury, p. 24, closing the meeting