By the start of the XXIst century, seasoned UFO researcher Jacques Vallée had an ominous realization: parsing through modern sighting reports to detect true anomalies from man-made objects and common atmospheric phenomena was getting harder and harder, because our skies were getting cluttered with all sorts of artifacts: geo-synchronous satellites, the international space station (ISS), aircraft of all kinds—including unmanned drones, which were just getting introduced in the mass market—were easily confused by untrained observers. And to compound the situation, the US government and other nations were deliberately obfuscating the data, by exploiting belief in the UFO phenomenon to conceal classified technology. How then to tell apart the proverbial alien wheat from the terrestrial chaff?
The solution to Jacques—a lover of old books and dusty libraries—was to look into the past rather than focus on the present. In 2009, he and his colleague Chris Aubeck released ‘Wonders in the Sky’ in which they gather more than 500 carefully selected cases of aerial anomalies, from Biblical times to the dawn of the Industrial age (1879) before mankind’s ingenuity allowed us to venture above the surface of the Earth.
Some seven years later, astronomer Beatriz Villarroel came up with a similar methodology in the search of what she and her colleagues call ‘non-terrestrial artifacts’ (NTA) close to or orbiting our planet: analyzing the digitized photographic plates taken by the Mount Palomar astronomical observatory’s Sky Survey (POSS I) in the 1950s—before the start of spaceflight and Sputnik (1957)— and compare them with plates of the same portions of the night sky taken by the same observatory thirty years later (POSS II). If the plates showed bright star-like spots in the 50s survey which were absent in the 80s survey, and after you eliminated all emulsion errors and scanning artifacts, whatever was left would be indicative of an NTA which could not be explained by any known astronomical phenomena (stars don’t tend to ‘disappear’). The evidence would be even more robust, if a group of three or more ‘transient objects’ were shown aligned within a single plate, because that would suggest the anomaly (or anomalies) were moving during the 50-minute exposure time of the photograph.
In other words, if there was anything circling the Earth before both the Americans and the Soviets had the means to launch anything into space yet, then what is it and who put it there?
In 2021 Villarroel and her colleagues published a paper using the data gathered by the ‘Vanishing & Appearing Sources during a Century of Observations’ project (VASCO)—a citizen-scientists group she organized to visually look for potential star-like transients— that showed nine strong possible candidates that appeared and disappeared simultaneously on one of the 1950s POSS I plate.
In 2023, they went even further by detecting one transient which was captured in a plate on July 19, 1952. That date might not mean much to common folk unfamiliar with UFO lore, but it eerily coincides with one of the most significant events in ufological history: the flap over Washington D.C. in which multiple witnesses (including airborne pilots and radar operators) reported multiple unidentified objects flying over the capital of the United States. The incident prompted the first press conference by the US Air Force since the end of the World War in 1945 to calm the public—the official explanation was that the UFOs were nothing but a ‘thermal inversion’ which had managed to fool even the radar equipment…
And now Villarroel and her colleagues have published another paper updating their research, pointing to more strong candidates for possible NTAs, and responding to colleagues who have tried to refute their findings by claiming the transient anomalies are just emulsion errors (or some other developing artifacts on the old photographic plates), by showing how there’s an statistical absence of these transients on the portions of the sky which correspond to the Earth’s shadow; which would indicate not only the transients are physical objects, but their brightness is probably caused by the glint on their surface reflecting off solar light—emulsions should be distributed randomly regardless of where the shadow of the Earth is cast, and yet Villarroel’s transients aren’t.
Furthermore, another one of the anomalies detected corresponds with the peak of another major UFO wave, which took place in 1954—incidentally, it was during that time that sightings of occupants entering, or in the vicinity of the objects, began to gain traction in the reports; which would result in the coining of the term ‘close encounters of the third kind’ (CEIII) by Dr. J. Allen Hynek.
[T]he fact that these transient alignments appear preferentially within a day of reported UAP events strongly disfavors instrumental or spurious origins.
[…]Additionally, a correlation has been found between VASCO transients and historical nuclear test dates (Bruehl & Villarroel 2025), echoing past statistical studies linking nuclear activity to increased UAP reports, see e.g. review by Knuth et al. (2025). While causality remains undetermined, the convergence of these independent correlations suggests that the VASCO transients are not random artifacts, but potentially linked to physical phenomena worthy of further investigation.
Aligned, multiple-transient events in the First Palomar Sky Survey (July 2025). Villarroel, Solano, Guerguori, Streblyanska
Even though it’s way above my paygrade I went through the paper, and the section I found more interesting is when they argue about the brightness of the transients corresponding to solar reflection, by testing different topologies of hypothetical NTAs using the 3d modelling software Blender. The team created 3d objects with varying geometries—a cone-like shape like a layered cake, a regular polyhedron, a sphere, a double pyramid, and an irregular structure composed of different panels—in order to test whether they could simulate the star-like appearance observed in the POSS I plates in a way that would match the angle of the Sun’s light at the time they were taken, using different rotation and precession speeds.
Although their results are speculative, they seem to support the notion that only a small portion of the surface in their hypothetical NTAs would have mirror-like reflective qualities, which could correspond with the short, distinct glints shown in their studied alignments—i.e. if the objects were entirely reflective, or self-illuminating, then they would appear as a long streak on the plate. These are also the same reasons why they dismiss the possibility the transients were captured inside the Earth’s atmosphere during the photo’s exposure.
I wonder why Villarroel didn’t choose to test this hypothesis using the shapes more regularly observed in UFO reports, like the typical dome-shaped disk which is more commonly associated with the phenomenon even to this day. I suppose she was careful not to design her experiments as if they were intended to prove the existence of ‘flying saucers’, even though she’s partly supporting her arguments through the citing of historical UFO reports from that era.
And therein probably lies the main Achilles hill of her argument, because even though the stigma surrounding the UFO phenomenon has weakened as of late (and perhaps only temporarily, as in other occasions) Villarroel is asking her astronomy colleagues to take UFO reports at face value; a big step I suspect many of them are not ready to take… yet.
The other aspect of her work I find troublesome is that it is too reliant on an ETH assumption, in which her NTAs would be evidence of extraterrestrial probes surveilling the Earth—a surveillance that coincided with the pioneering tests of nuclear technology, according to the popularized interpretations of modern ufology. Going through what little of their mathematics I could follow, it is clear their analysis is deliberately trying to come up with a number of candidates that is small enough as to not be ‘scientifically offensive’ to her colleagues. A strategy that I—a layman who is also a seasoned UFO buff—find somewhat ironic; since it was precisely the high number of UFO reports what drove investigators like Vallée and Hynek to eventually discard the extraterrestrial hypothesis, and start to explore more challenging ideas.
Nevertheless, it is undeniable that Villarroel’s work is a breath of fresh air in her attempts of applying scientific tools, through a very ingenuous approach, in the search for evidence of UFO activity; using means and methods openly available to civilian scrutiny that are not dependent on classified data restricted under the pretext of ‘national security’.
If proven right, Villarroel might force us to accept that at least some UFO reports do have a correlation with astronomical phenomena. That would indeed by a wonder to witness.
