Los Alamos Conference on Aerial Phenomena, 1949

A verbatim transcript of a February 16, 1949 classified conference at Los Alamos Scientific Laboratory on the 'green fireball' phenomenon reported near Los Alamos and Kirtland AFB since December 1948. Attendees included Edward Teller, Norris Bradbury (Los Alamos director), Frederic Reines, meteor expert Dr. Lincoln LaPaz, and Army/AEC security officials. LaPaz, drawing on his own Dec. 12, 1948 sighting and transit-based azimuth/elevation measurements, argued the fireballs were not conventional meteors: consistently horizontal paths at 8-10 mile altitudes, an unusual yellow-green color never recorded in ordinary meteor observations, near-constant velocity (3-12 mi/sec) over long distances, no sound, and no recovered fragments or debris trail despite extensive searches. Teller performed extensive on-the-spot calculations and offered that, if the sound-absence data were taken at face value, the object might be very small (~1 cubic centimeter) or 'an electron phenomenon' rather than a solid meteor. No consensus was reached; Bradbury closed the meeting still uncertain, calling both the horizontal path and the sound absence 'puzzling.'

Why this rating Multiple independent, credentialed witnesses (including a professional meteor astronomer with transit-based measurements) across widely separated locations describe consistent characteristics -- horizontal high-altitude paths, an atypical color, and total absence of sound or recovered debris -- that the assembled physicists could not fit to a conventional meteor model; not 'strong' because all data is visual/eyewitness with no photographic or instrumented capture, and no consensus alternative explanation, extraordinary or otherwise, was reached.

• DocumentDOE-UAP-D004Release 4

  DOE-UAP-D004, Los Alamos Conference on Aerial Phenomena, 1949

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• Unverified

  LaPaz argued the green fireballs' consistently horizontal, near-constant-velocity paths at 8-10 miles altitude are inconsistent with any known conventional meteor behavior.

• Unverified

  No sound was ever confirmed accompanying a green fireball despite systematic follow-up interviews, unlike ordinary meteorite falls which are reliably accompanied by detonation or rushing sounds.

• Unverified

  If the reported data (brightness, absence of sound) were taken literally, physical calculation suggested the object would have to be extremely small (on the order of 1 cubic centimeter) to avoid producing an audible shock wave.