Transient 'objects' after nuclear tests are quite possibly high energy radiation from the tests themselves. Remember these are on film, and the film is likely removed from its protective housing for some time before, during, and after imaging. (And in many cases protective housing wouldn't help anyway.)

I get the sense that this topic is popular because "aliens y'all". It's much more likely to be radiation. It's possible that atomic tests kick luminous particles into the upper atmosphere. But it's not aliens.

The lead author on this paper is a professor of anesthesiology. I think it's fairly safe to describe its conclusion as crank-adjacent, if not outright cranky.

Awhile ago I built my own ML pipeline to automate scanning these plates, it was very revealing. Beatriz and her team were very helpful.

https://arxiv.org/abs/2604.04810

One of the authors, Beatriz Villarroel, has been interviewed on this topic several times. She has never said "its aliens". She just says its interesting and warrants investigation. She is also a little stunned that nobody has investigated pre-sputnik transients before.

What's more interesting is that a third of these plates were destroyed by Donald Howard Menzel without reason or explanation.

From Wikipedia: "During World War II, Menzel was commissioned as a lieutenant commander in the United States Navy and asked to head a division of intelligence, where he used his many-sided talents, including deciphering enemy codes. Even until 1955, he worked with the Navy improving radio-wave propagation by tracking the Sun's emissions and studying the effect of the aurora on radio propagation for the Department of Defense.[3][4] Returning to Harvard after the war, he was appointed acting director of the Harvard Observatory in 1952, and was the full director from 1954 to 1966. His colleague Dr. Dorrit Hoffleit recalls one of his first actions in the position was asking his secretary to destroy a third of the plates sight unseen, resulting in their permanent loss from the record."

The "diminish significantly in Earth's shadow" part makes me think it's sunlight glinting off spyplanes. The B-47 was shiny.

"Now, we're not saying its aliens but coincidentally here's a recent paper authored by some of us:"*

A cost-effective search for extraterrestrial probes in the Solar system

https://academic.oup.com/mnras/article/546/2/staf1158/822188...

*Not an actual quote

This is exactly the kind of research meant to be on preprint servers like arxiv.org

From Beatriz Villarroel -I guessed it without opening the link-, right?

On the papers, it doesn't mean that it must be aliens, but weird phenomena.

> For example, is it possible that unknown to the public there were multiple launches of artificial satellites long before Sputnik with some launches timed to coincide with U.S. nuclear tests? Or rather, do the current findings represent detection of a non-human technosignature? Due to data limitations, such hypotheses cannot be subjected to falsification.

"Idk, therefore aliens" is not good science.

Not saying...

I read the pre-publishing version of this paper, and there was then and still is a serious problem with their logic, consistent with if not bad faith, something akin to it:

Assume for a moment their core hypothesis is correct, there were transient objects captured on film pre-Sputnik in LEO objects.

What might we say about their nature?

The authors' undisguised implication is "it's aliens" to be blunt; that's their motivation for this work.

Consequently they put effort (which may not be noted in the final published papers...) into the question of whether they could make any meaningful inference about the geometry and spectral properties of their "transients," their interest (of course) was that if they could make a meaningful argument for regular geometry, they had the story of the century in effect.

These efforts failed totally.

A natural inference might be, among the reasons this might be, is that the objects (remember we are assuming they exist) do not have such characteristics. The primary reason that would be true is if they were naturally occurring objects.

I looked this up and was surprised to learn that there are currently estimated to be on the order of a million small objects in the inner solar system.

So: the entire hypothesis hinges on "significant correlation with nuclear testing." Because otherwise, once can reasonably assume that transient traces of objects—when they are actually traces of objects—would in a quotidian way presumably be caused by some of these million objects.

Or so say I.

There is no end of peculiar and provacative history and data in UFOlogy, and even more murk; one needs to tread very carefully to not go down (or, be led down) to false conclusions, disinformation, and the like.

The authors of this paper seem singularly disinterested in that caution.