Sighting waveThe Green Fireballs of New Mexico (1948-1951)

aka The Green Fireballs of New Mexico (1948-1951)

A wave of vivid green, near-horizontal, silent fireballs over New Mexico's nuclear and military sites beginning December 1948 led meteoriticist Dr. Lincoln LaPaz to argue they were not ordinary meteors, prompting Project Twinkle (1950-51) - the first official US instrumented optical study of an aerial anomaly - which collected too little data to resolve the case.

phenomenologically-open Held phenomenologically-open. The sighting wave and its clustering near New Mexico nuclear sites are documented in declassified records, as are LaPaz's anti-meteor arguments, the 1949 Los Alamos conference, and Project Twinkle. But the central question - ordinary unusual meteors (Menzel) versus genuinely anomalous objects (LaPaz) - was never resolved, because the first official instrumented study under-performed and obtained no conclusive spectra or triangulation. The case's distinction is as an early apparatus-event (an instrumented attempt) that failed to yield resolving data, leaving a real but under-measured phenomenon open rather than closed.

status history (1)

2026-06-14 · new → phenomenologically-open — seeded 2026-06-14 — corpus-growth pass (first instrumented US anomaly study; nuclear-proximity)

▸ Deep dive — full timeline, named personnel, sensors, theory-by-theory analysis, and the conventional explanations weighed against the open questions →

Beginning around 5 December 1948, aircraft crews and ground observers reported brilliant emerald-green fireballs over New Mexico, concentrated near Los Alamos, Sandia, and Kirtland AFB. Dr. Lincoln LaPaz of the University of New Mexico’s Institute of Meteoritics argued the objects were atypical of meteors - too slow, near-horizontal, intensely green, with no recovered meteoritic fragments, persistent dust trail, or sound - and at one point suspected artificial (Soviet or secret US) origin. A 16 February 1949 conference at Los Alamos drew LaPaz, upper-atmosphere physicist Joseph Kaplan, Edward Teller, and lab director Norris Bradbury, plus Army, Air Force, FBI, and AEC representatives, but reached no agreed origin (Teller reasoned on a blackboard that a silent object ‘could not be a material body passing through the air,’ leaning toward an electrical phenomenon). The Air Force set up Project Twinkle (Dec 1949 / 1950 - Nov 1951), an instrumented study with cinetheodolites and spectrographic cameras intended to photograph and analyze the fireballs; it was under-resourced (often one station instead of three), kept missing the phenomenon, and was discontinued as inconclusive. Mainstream astronomers (Donald Menzel) held them to be unusual meteors; LaPaz disagreed. The case’s lasting importance is as the FIRST official, instrumented US attempt to capture an aerial anomaly - a measurement effort whose apparatus underperformed, leaving the phenomenon open.

Notable & intriguing

A 15 September 1950 Air Materiel Command memo noted, of Project Twinkle, that ‘it may be considered significant that fire balls have ceased abruptly as soon as a systematic watch was set up’ - the instrumented study kept failing to catch them.

AMC memo, quoted in the David Darling Encyclopedia (Project Twinkle); Project Twinkle Final Report (Nov 1951)
At the 16 February 1949 Los Alamos conference, Edward Teller worked the problem on a blackboard and concluded the silent fireballs ‘could not be material objects passing through the air,’ favoring an electrical/electron phenomenon - while Lincoln LaPaz argued they were not ordinary meteors and possibly artificial.

Project 1947, “Scientific Advisory Board Conference on Aerial Phenomena, 16 February 1949”

Public-record items already documented about this subject. Folklore is labelled. Sources cited where the specificity warrants it.

More — sighting wave