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.
But to me the biggest flag is that these images are from 50 minute exposures. The objects don't appear as streaks, so they are either very, very short flashes (much shorter than 50 min), or they are very far away. The authors interpret this to mean the objects should be in geosynchronous orbit, which doesn't make sense; objects in geosync would still appear to move relative to the star background over the course of 50 min. Yet this is the entire basis for their "shadow deficit" window calculation. You could constrain the duration vs distance by looking at the effect it would have on smearing the PSF, which would be interesting.
Overall it seems pretty unscientific. If you go looking through enough statistically noisy data for signals in enough places, you'll eventually find it.
There are other possiblities that are likely: Upper atmosphere tests resulting in transient luminous phenomena. This would be more likey in certain conditions where the sun could reflect off of specular matter (e.g., bits of metal). You would see this most likely within 1-2 hours of sunset or 1-2 hours of sunrise (source: I've used optical equipment to spot satellites professionally).
I'd note that thier pipeline for removing "plate defects" is not based on the PSF but on some vaguely defined "expert review" training. This can, and should, be a quantifiable step.
Couldn’t be aberrations in equipment, like lenses? Or film development?
> Overall it seems pretty unscientific.
1) The paper is suggesting aliens... your suspicion hats should always go on
- Carl Sagan said: "Extraordinary claims require extraordinary evidence". Is the evidence extra-ordinary?
2) The authors aren't experts
- Stephen Bruehl: A doctor of Anesthesiology
- Brian Doherty: "Independent Researcher"[0]
- Alina Streblyanska: Actually maybe a astrophysics researcher?[1]
- Beatriz Villarroel: The top Google hit for her is for a UFO wikipedia[2]
3) Authors don't share affiliations
- Corresponding author has no domain expertize and no clear affiliation to others.
4) Authors have hints of metric hacking
- Villarroel has 8 citations in a paper with only 18[3]
5) The GitHub repo is dead: https://github.com/dca-doherty/VASCO-ML
If you do understand statistics there's clearly more red flags. The +/- windowing being a pretty big one, since there are much better tools for this (errors don't need to be symmetric! Nor do they need to be uniform!). There's also a pretty big assumption made that cshimmin didn't mention: the paper assumes all nuclear tests are in the public record. But I also assume if you have a strong statistics background then there's a high probability you didn't upvote the post.
[0] The man has effectively no online presence. Google searching his email yields effectively nothing except people posting about this paper in UFO groups (https://www.google.com/search?q=%22briandohertyresearch%40gm...). His linked GitHub also makes him anonymous (https://github.com/dca-doherty/) and his website linked is just about finding day care in Texas. He has one more paper on ArXiv, but it is from a few weeks prior
[1] Found their Linkedin (https://www.linkedin.com/in/alina-streblyanska-95b2375b/). Their most recent paper is also on UAPs, along with Villarroel. But also, they work for "Society of UAP Studies", which should be a big red flag. Also, they were working as a Post-doc for 12 years, which is a bit insane
[2] https://www.wikidisc.org/wiki/Beatriz_Villarroel and here's here Google Scholar https://scholar.google.com/citations?user=_Jc8gm0AAAAJ
[3] I looked at some other papers of hers and they show a similar pattern. This explains her citation count (which is rather low) and h-index (it's better to just click on the references and you'll see it's predominantly her referencing herself):
- 2602.15171: 9 citations total, 8 are hers
- "A cost-effective search for extraterrestrial probes in the Solar system" has many more, but still 6 to herself (and 3 to Loeb)
- Transients in the Palomar Observatory Sky Survey (Yes, this is in "Nature"): 20 citations, 5 hers
- Aligned, Multiple-transient Events in the First Palomar Sky Survey: 11/36
- On the Image Profiles of Transients in the Palomar Sky Survey: 5/5
- A Civilian Astronomer's Guide to UAP Research: 7/98 (actually not a red flag, but the title sure is...)
- and so onSecond, and perhaps more importantly, is that there's a detailed criticism of this line of research available, including evidence against the argument that these are more likely ±1 day of nuclear tests. See https://arxiv.org/pdf/2601.21946, and also https://arxiv.org/pdf/2402.00497 for a study of plate defect issues.
I think the current paper continuing this line of research should be read cautiously. I don't love discounting ideas out of hand, as these folks clearly have put effort into the analysis. But the rebuttals read as at least as high quality analysis, and "it's aliens" requires a lot of evidence for me to take it seriously.
another POV is the paper is sloppy in the parts that matter
Machine Learning goes both ways. A chatbot is not predisposed to ruin aliens enthusiast's days. It just does what it is told to do, like repro a paper, and it can tell you the problems in some limited, but globally important, objective way, and it did, and the paper has problems, and they're basic.