For UFO enthusiasts, this is excellent news. But for scientists, the matter is quite a puzzle. An article published on the scientific pre-publication platform arXiv, analyzing mountains of pre-Sputnik archives, argues that the transient events observed before the space age – short-lived light phenomena, identified from photographic plates – highlighted by the project Vanishing & Appearing Sources During a Century of Observations (Vasco) did indeed exist.
“These short-lived transients, of less than 50 minutes of exposure, are absent from images taken shortly before their appearance and images from subsequent observationswrote the experts. In some cases, several of them appear in a single image, with characteristics that are difficult to attribute to ordinary causes.”
Other results also seemed troubling, IFL Science reports. In a study published in 2025, astronomers detected a correlation between transients and nuclear tests, with the probability of observation increasing by 45% during these periods. Could extraterrestrials have come to watch the show from space? Not sure.
Several more… down to earth hypotheses were formulated: the aerial phenomena would have been captured by chance on the photographic plates and could be attracted towards the Earth by the experimental explosions. A second hypothesis suggests that it is an unusual and still unknown atmospheric phenomenon, potentially linked to nuclear tests.
A follow-up study added a layer of mystery, finding that these transient events occurred less frequently in an area in Earth’s shadow. An intriguing detail: if these objects exist physically, their visibility would then depend directly on the light they reflect.
Brief flashes of light
Today, the pre-publication criticizes, among other things, the absence of microscopic analysis of the photographic plates. Researcher Ivo Busko examined plates from other observatories for the pre-space period, including those from the Hamburg Observatory.
Verdict: “We obtain results that appear to independently confirm the presence of such transientsindicates the study. Although work is still ongoing, our results point in the direction of the findings of the Vasco project, particularly with regard to the signatures of brief optical bursts.”
The detected events thus have a width systematically narrower than that of a star’s spread, suggesting that the transients resemble extremely brief flashes rather than persistent objects.
Although an astronomical mystery is always fascinating, it is too early to get excited. Lightning on a plate does not mean that aliens will visit us during the next nuclear tests. The link with nuclear testing remains, at this stage, unexplained.
