Los Alamos green fireballs conference
Transcript of the February 16, 1949 conference at Los Alamos Scientific Laboratory at which physicists attempted to explain the green fireballs observed over New Mexico nuclear-weapons sites in late 1948 and early 1949. Released through PURSUE Release 04 on July 10, 2026 as DOE-UAP-D004.
This case predates PURSUE, so the primary record was never centrally digitized. The source links below point to the best public records available: original investigators, primary reporting, and diagnostic-friendly secondary analysis. For PURSUE-era cases, mirrored files render inline further down.
Mirrored files
1 file for this case, served from our first-party mirror.
DOE-UAP-D004 · pdf · Release 04
Provenance metadataFields marked “not disclosed” are transparent gaps in the release, not omissions on our end.
- Coordinates
- Los Alamos Scientific Laboratory, New Mexico (approximately 35.9°N 106.3°W); sightings across Los Alamos, Sandia (Albuquerque), Kirtland AFB
- Altitude
- Reported green-fireball observations at low-atmospheric altitudes (below typical meteor bolide altitudes); precise altitude not resolved at time of conference
- Sensor detail
- Naked-eye visual observations by named DOE, Sandia, and Kirtland personnel; no instrumented sensor data at time of conference (Project Twinkle later established as instrumented follow-up)
- Witness count
- Multiple witnesses across three nuclear-adjacent installations, November 1948 through February 1949
- Operational context
- Cold-War-era nuclear-weapons research program; the fireball observations occurred during heightened activity at the primary US atomic-weapons laboratories
- Weather / visibility
- Winter conditions in the New Mexico high desert; multiple observations at dusk or after dark
- Chain of custody
- Los Alamos and Sandia site observations → AEC internal correspondence → February 16, 1949 conference minutes → Los Alamos file → AEC successor DOE → PURSUE Release 04
- Classification
- Originally CLASSIFIED (AEC RESTRICTED DATA); DECLASSIFIED PER PURSUE, July 10, 2026
- Encounter duration
- Not disclosed in this release
Official description
DOE-UAP-D004: transcript of the Los Alamos Conference on Aerial Phenomena, held February 16, 1949 at Los Alamos Scientific Laboratory. Attending physicists included Edward Teller, Norris Bradbury, Lincoln LaPaz (University of New Mexico meteoriticist), and staff from Sandia and Kirtland Air Force Base. The conference addressed a series of green-fireball observations over Los Alamos, Sandia, and Kirtland between November 1948 and February 1949.
Editor's context
The green fireballs were among the earliest post-war UAP incidents whose location and consistency made them a serious concern to the US atomic-weapons infrastructure. LaPaz argued the objects were not consistent with any known meteoritic phenomenon (unusual color, controlled trajectory, low apparent altitude). Edward Teller argued a natural explanation was still possible. The 1949 conference did not resolve the question and led directly to the establishment of Project Twinkle (1949-1951), a dedicated USAF sky-photography instrument program deployed at White Sands specifically to catch the fireballs on camera.
Prevailing explanation
What scientists and analysts generally think
Modern consensus attributes the majority of the 1948-1949 green fireball events to unusual bolides, meteor showers, or copper-bearing meteoric material, though a residue of hard cases remains unexplained. Project Twinkle failed to obtain instrumented data during its two-year run, which itself is treated as either evidence of very low base rate or as an argument for exotic explanations, depending on interpretive frame.
In the margins
Transcribed redactions, stamps, and handwritten markings, the paratext of the file. Often the most human part of a declassified document, and worth reading on its own.
- Stampp. coverLOS ALAMOS SCIENTIFIC LABORATORY, CONFERENCE MINUTES
- StampDECLASSIFIED PER PURSUE, July 10, 2026
- AnnotationAttendees named in transcript: Edward Teller, Norris Bradbury, Lincoln LaPaz, plus Sandia and Kirtland staff.
- AnnotationConference topic: green-fireball observations Nov 1948 through Feb 1949 over Los Alamos, Sandia, and Kirtland.
- AnnotationDirect outcome: establishment of Project Twinkle (1949-1951), USAF sky-photography program at White Sands.
Cite the primary source
Citations center the originating government agency and link to the official record. This archive is listed as the access point, not the author.
U.S. Government. "Los Alamos green fireballs conference." Released via PURSUE program, 2026-07-10. File ID: PURSUE DOE-UAP-D004. https://www.war.gov/UFO/release/04/. Accessed 2026-09-05 via Social Media for Aliens archive, https://socialmediaforaliens.com/files/los-alamos-green-fireballs-1949.
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