DOW-UAP-D017, UAP Reported at Sandia Base, 1948-1950

From Declassified U.S. Government Records: The Sandia Base UAP Incidents, 1948-1950

Between December 1948 and May 1950, military observers and scientists at and near Sandia Base in New Mexico reported seeing more than two hundred unusual aerial objects. This file documents their accounts and the early scientific investigation into the sightings.

Most of what witnesses described fell into two categories. Some reported bright green fireballs that moved slowly through the sky, almost horizontally, and then vanished. Others reported disc-shaped objects or fireballs of different colors. Military pilots, atomic energy security inspectors, and scientists at nearby Los Alamos submitted reports. No sounds accompanied the sightings. No debris was found. Scientists at the time could not identify the objects.

The green fireballs appeared most often in the evening hours, between roughly 5 p.m. and 11 p.m. They moved at speeds faster than aircraft but slower than typical meteors. They fell along northward approach paths far more often than random chance would predict. Several sightings clustered on weekends. An analysis decades later noted a curious coincidence in timing with Soviet Urals region morning hours.

Scientists examined dust collected after some incidents and found copper particles in certain samples. Dr. Lincoln LaPaz, director of the Institute of Meteoritics at the University of New Mexico and a leading consultant on the sightings, noted that copper is extremely rare in genuine meteorites. He also compiled a list of ten significant differences between these green fireballs and typical meteors. He leaned toward attributing them either to meteorites of unusual composition or to U.S. guided missiles under test.

The records show that the U.S. Air Force's 17th District Office of Special Investigations at Kirtland Air Force Base took the matter seriously enough to establish a formal reporting system for the New Mexico area in December 1948. Conferences were held at Los Alamos in February and October 1949 to discuss the phenomenon. Representatives from the FBI, the Atomic Energy Commission, the Scientific Advisory Board, and military intelligence attended. No consensus explanation emerged. The investigation became the basis for Project Grudge, a broader U.S. Air Force effort to collect and analyze flying object reports from military installations nationwide. By May 1950, the monthly frequency of sightings had declined, even as reports of other types of aerial objects in the region had increased.