Project Blue Book Case File
Kirkland AFB, N. M., December 1948December 1948
Summary
On December 5, 1948, a U.S. Air Force pilot flying from Colorado to Arizona reported seeing an unusual green flare near Las Vegas, New Mexico. Within hours, other military and civilian witnesses reported similar green lights in the same region. Over the next few days, sightings continued in the skies above New Mexico, with observers describing luminous fireballs that moved in ways unlike typical meteors. By December 12, the incidents had attracted the attention of the U.S. Air Force Office of Special Investigations at Kirtland Air Force Base.
The most detailed sighting occurred on December 12, when astronomers and security personnel at Los Alamos and near Bernal, New Mexico, observed a bright green fireball traveling from east to west at a low altitude. Unlike ordinary meteors, which fall from great heights and accelerate earthward, this object moved almost horizontally at an estimated 8 to 12 miles per second. It left no audible trace, left no meteoritic debris, and seemed to have a controlled trajectory before breaking apart into smaller fragments near its disappearance point.
Dr. Lincoln LaPaz, director of the University of New Mexico's Institute of Meteoritics, took personal charge of the investigation. He interviewed witnesses, plotted the paths of the observed fireballs, and analyzed their characteristics. LaPaz concluded that the objects could not be ordinary meteors. He noted that normal meteors show erratic brightness patterns, fall from altitudes of 40 miles or more, reach much higher speeds, and leave behind trails of sparks and sound. The December fireballs appeared suddenly at full brightness, moved at moderate speeds, remained only 3 to 10 miles above the surface, traveled in nearly horizontal paths, made no sound, and produced no sparks. The intense green color, which LaPaz determined matched the wavelength of burning copper compounds, was also highly unusual for meteoric phenomena.
LaPaz recommended a thorough investigation of the incidents and proposed that military and civilian observers in New Mexico be alerted to report any future sightings. He also suggested field searches be conducted in the areas where the fireballs disappeared, with the goal of recovering physical evidence and determining the true nature of the objects. The Air Force noted that no research involving flares or lighting devices was known to be underway at regional military installations, including Holloman Air Force Base.
The USAF evaluation of this case was listed as unknown. The full case file, containing 135 pages of investigative reports, interviews, and analysis, is held by the National Archives on microfilm.
Reported location
Kirkland AFB, N. M., December 1948
Date of incident
December 1948
State / country
? / XX
Page count
135 scanned pages
USAF evaluation
unknown
Microfilm
T1206, Roll 4