Los Alamos, New Mexico UFO Sighting (March 1947) — FBI Files
FBI files document a luminous, color-changing object descending and exploding over Los Alamos, New Mexico, in March 1947.
Background
In March 1947, in Los Alamos, New Mexico, U.S. government investigators recorded an unidentified-object incident later released to the public on May 8, 2026, as part of the Presidential Unsealing and Reporting System for UAP Encounters (PURSUE). The incident occurred during a period of heightened atmospheric and geopolitical tension in the post-World War II era. During this time, the United States was navigating the early stages of the Cold War, a period characterized by rapid advancements in aerospace technology and an increasing preoccupation with aerial surveillance and national security. The geographic location of the sighting, Los Alamos, held significant strategic importance due to its role as a center for nuclear research and development.
This specific case is one of the first wave of “flying saucer” reports that swept the United States after the Kenneth Arnold sighting of June 1947 and the Roswell incident of July 1947. While the Arnold sighting is often credited with popularizing the term “flying saucer,” the Los Alamos event predates those famous occurrences, suggesting that unidentified aerial phenomena were being observed and documented by authorities even before the phenomenon entered the broader public consciousness. The case was filed with the Federal Bureau of Investigation, whose Knoxville, Albuquerque, Los Angeles, and other field offices routed UFO reports to headquarters under the Bureau’s standing protocols for the protection of vital installations. This procedural routing indicates that the federal government viewed such sightings through the lens of potential threats to sensitive military and scientific sites.
What the document records
Observers in Los Alamos, New Mexico, witnessed a tremendous, luminous object descending from a high altitude. The object formed an arc and appeared to change color, initially yellow and then white/blue, before plunging towards the earth. Two explosions were reported before the object disappeared from view. The number of witnesses is not specified in the released document.
The description of the object’s descent and its chromatic shifts aligns with certain characteristics observed in other high-altitude atmospheric phenomena, yet the reported explosions and the specific trajectory of the object distinguish it from more routine aerial events. The documentation focuses on the visual trajectory and the luminous qualities of the object, providing a primary account of its movement through the New Mexico sky.
Type of case
The case is a visual sighting reported by ground or air observers.
Status
All records released under the PURSUE program are designated unresolved by the All-domain Anomaly Resolution Office (AARO) by default. The federal government has not concluded that the events were anomalous, has not concluded that they were conventional, and has not ruled out either possibility.
When evaluating unidentified aerial phenomena from the late 1940s, investigators often consider a variety of conventional candidates. These include experimental aircraft being tested in the sensitive airspace surrounding New Mexico, weather balloons, and specifically the Project Mogul series of high-altitude balloons designed to detect Soviet nuclear tests. Other possibilities include atmospheric optical phenomena such as sundogs, which can create colorful arcs, or lenticular clouds, which can appear as stationary, disc-shaped objects. Astronomical objects, including the planet Venus, the Moon, or meteors passing near the horizon, are also frequently analyzed in such cases. Despite these possibilities, the specific details of the Los Alamos sighting, particularly the reported explosions and the color-changing arc, remain officially unclassified and unverified.