In the early 1950s, astronomers at the Palomar Observatory in California captured images of the night sky that revealed something peculiar: fleeting, star-like objects that appeared and vanished within minutes.
These “transients,” as scientists call them, were spotted during the first Palomar Observatory Sky Survey, a project that photographed the heavens before the launch of the first artificial satellite in 1957.
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Subscribe to the NewsletterA recent study by researchers Stephen Bruehl from Vanderbilt University Medical Center and Beatriz Villarroel from Nordita in Sweden suggests these mysterious flashes might be linked to two surprising phenomena: above-ground nuclear weapons tests and reports of unidentified anomalous phenomena, commonly known as UAPs or UFOs.
The researchers combed through a massive dataset spanning from November 1949 to April 1957, analyzing over 100,000 transients detected in the sky survey’s images.
These transients were bright, point-like sources that appeared in one photograph but were absent in images taken just before or after, ruling out stars or other known celestial bodies.
The team wondered if these brief apparitions could be connected to human activity on Earth, specifically nuclear tests conducted by the United States, Soviet Union, and Great Britain, or to the wave of UAP sightings reported during the same period.
To explore this, they compiled a detailed record of 2,718 days, noting when transients appeared, when nuclear tests occurred, and when UAP sightings were documented in a comprehensive database called UFOCAT.
Days within a three-day window of a nuclear test—meaning the day of the test plus the day before and after—were 45% more likely to have transients than other days. Moreover, on those same days, the number of transients was significantly higher, suggesting a possible link between nuclear explosions and these fleeting sky objects.
The study found that on days when at least one transient was observed, the number of UAP reports was noticeably higher. For every additional UAP sighting reported on a given day, the number of transients increased by about 8.5%.
This pattern held even when the researchers accounted for the fact that UAP reports were common, occurring on nearly 90% of the days studied.
The link was strongest when both a nuclear test and a UAP sighting happened on the same day, hinting that these events might amplify each other’s effects on transients.
One particularly compelling observation came from July 1952, when multiple transients appeared in sky survey images on two consecutive weekends. These dates coincided with a famous series of UAP sightings over Washington, D.C., where objects were seen both visually and on radar for hours.
The researchers speculate that some transients could be UAPs in Earth’s orbit, reflecting sunlight or emitting light as they descend into the atmosphere, possibly triggering sightings on the ground.
The study doesn’t claim that transients are definitely UAPs or caused by nuclear tests, but it rules out simpler explanations like defects in the photographic plates.
Unlike streaks that might result from atmospheric effects, these transients appeared as distinct points, suggesting they were objects at high altitudes or in orbit.
The researchers propose two possibilities: the transients could be an unknown atmospheric phenomenon triggered by nuclear detonations, or they might be artificial objects, perhaps linked to the long-standing idea that UAPs are drawn to nuclear activity.
The Palomar Observatory’s single vantage point also limited the study, as nuclear tests and UAP sightings occurred worldwide. Still, the findings add weight to the idea that transients are real phenomena, not just photographic flaws.
Historically, numerous UFO incidents have been reported near nuclear test sites, adding context to these findings. For instance, during the 1940s and 1950s, sightings of unusual objects were frequently noted at locations like Los Alamos and Nevada Test Site, where nuclear weapons were developed and tested.
Military personnel and scientists reported metallic, fast-moving objects in the skies, often during or shortly after tests. These documented accounts suggests a pattern of UAP activity near nuclear facilities that may extend to the transients observed in the sky survey.
