{"id":154276,"date":"2025-10-30T23:53:22","date_gmt":"2025-10-30T23:53:22","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/154276\/"},"modified":"2025-10-30T23:53:22","modified_gmt":"2025-10-30T23:53:22","slug":"transient-flashes-in-50s-sky-plates-still-puzzle-scientists","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/154276\/","title":{"rendered":"Transient flashes in \u201950s sky plates still puzzle scientists"},"content":{"rendered":"<p><img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/Samuel-Oschin-Telescope-Palomar-Observatory-CA-e1761664187161.jpg\" alt=\"Big, white telescope dome with deep blue sky above it with many stars, appearing as short streaks.\" width=\"800\" height=\"515\" class=\"size-full wp-image-526188\"\/>The 48-inch (1.2 m) <a href=\"https:\/\/sites.astro.caltech.edu\/palomar\/about\/telescopes\/oschin.html\" rel=\"noopener nofollow\" target=\"_blank\">Samuel Oschin Telescope<\/a> at <a href=\"https:\/\/sites.astro.caltech.edu\/palomar\/homepage.html\" rel=\"noopener nofollow\" target=\"_blank\">Palomar Observatory<\/a>. This telescope was used in the 1st <a href=\"https:\/\/en.wikipedia.org\/wiki\/National_Geographic_Society_%E2%80%93_Palomar_Observatory_Sky_Survey\" rel=\"noopener nofollow\" target=\"_blank\">Palomar Sky Survey<\/a> (POSS-1), which recorded the mysterious transient flashes in the 1950s. Image via <a href=\"https:\/\/sites.astro.caltech.edu\/palomar\/homepage.html\" rel=\"noopener nofollow\" target=\"_blank\">Palomar Observatory<\/a>\/ California Institute of Technology.<\/p>\n<p><a href=\"https:\/\/helpsupportearthsky.org\/2025-donation-campaign\/\" rel=\"noopener nofollow\" target=\"_blank\"><strong>Science matters. Wonder matters. You matter.<\/strong><br \/>Join our 2025 Donation Campaign today.<\/a><\/p>\n<ul>\n<li><strong>Transient flashes of light<\/strong> \u2013 unusual short-lived light bursts \u2013 were 1st noticed in 2016 in photographic plates from the early 1950s Palomar Sky Survey. The mysterious lights sometimes appeared in straight lines or narrow bands. What were they?<\/li>\n<li><strong>Data analysis suggests the lights originated near Earth,<\/strong> possibly in high orbits or even geosynchronous orbits. But the 1st satellite, Sputnik 1, wasn\u2019t launched until 1957.<\/li>\n<li><strong>An updated analysis in 2 new peer-reviewed papers<\/strong> has found many additional transients. The new study hints at a possible correlation between early nuclear tests and possible UAP sightings in the early 1950s.<\/li>\n<\/ul>\n<p>Odd transient flashes of light in 1950s astronomical plates<\/p>\n<p>Some 1950s <a href=\"https:\/\/www.mariamitchell.org\/astronomical-plates-collection\" rel=\"noopener nofollow\" target=\"_blank\">photographic plates<\/a> \u2013 collected during the famous <a href=\"https:\/\/en.wikipedia.org\/wiki\/National_Geographic_Society_%E2%80%93_Palomar_Observatory_Sky_Survey\" rel=\"noopener nofollow\" target=\"_blank\">Palomar Sky Survey<\/a> in California \u2013 show short-lived flashes of light. Astronomers call them transient flashes. <a href=\"http:\/\/beatrizvillarroel.com\" rel=\"noopener nofollow\" target=\"_blank\">Beatriz Villarroel<\/a>, a researcher at Nordita at Stockholm University in Sweden, has been leading the investigation into these odd anomalies. She and her colleagues in the <a href=\"https:\/\/vasconsite.wordpress.com\/\" rel=\"noopener nofollow\" target=\"_blank\">VASCO Network<\/a> just published two new <a href=\"http:\/\/earthsky.org\/human-world\/what-is-peer-review\" rel=\"noopener nofollow\" target=\"_blank\">peer-reviewed<\/a> papers about them. VASCO stands for Vanishing &amp; Appearing Sources during a Century of Observations. The scientists <a href=\"https:\/\/www.su.se\/english\/news\/unexpected-patterns-in-historical-astronomical-observations-1.855042\" rel=\"noopener nofollow\" target=\"_blank\">said<\/a> on October 20, 2025, that their data suggest the flashes might be glints of sunlight off of objects in orbit around Earth. One problem: the flashes appeared before the first earthly satellite, <a href=\"https:\/\/www.nasa.gov\/history\/sputnik\/index.html\" rel=\"noopener nofollow\" target=\"_blank\">Sputnik 1<\/a>, launched in 1957.<\/p>\n<p>EarthSky first <a href=\"https:\/\/earthsky.org\/space\/9-weird-transients-palomar-observatory-1950\/\" rel=\"noopener nofollow\" target=\"_blank\">reported on these flashes<\/a> in 2021.<\/p>\n<p>Now, in the two updated papers, the researchers report new apparent patterns in the data. They said 68% of the transients flashed on the day after nuclear tests on the ground. There\u2019s also a possible correlation with <a href=\"https:\/\/earthsky.org\/earth\/uap-and-science-ufos-ualbany\/\" rel=\"noopener nofollow\" target=\"_blank\">UAP<\/a> reports \u2013 that is, reports of what the U.S. military and government calls Unidentified Aerial Phenomena, and what the rest of us call UFOs \u2013 in the same time frame. There were many such reports in the late 1940s and early 1950s, including some over <a href=\"https:\/\/www.amazon.ca\/UFOs-Nukes-Extraordinary-Encounters-Nuclear\/dp\/1544822197\" rel=\"noopener nofollow\" target=\"_blank\">nuclear test sites and weapons facilities<\/a>.<\/p>\n<p>The researchers published their peer-reviewed results in <a href=\"https:\/\/www.nature.com\/articles\/s41598-025-21620-3\" rel=\"noopener nofollow\" target=\"_blank\">Scientific Reports<\/a> on October 20, 2025, and in <a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">Publications of the Astronomical Society of the Pacific<\/a>. Both papers appeared on October 17, 2025. The new papers build on the previous results, which were <a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/1538-3881\/ab570f\" rel=\"noopener nofollow\" target=\"_blank\">published<\/a> on December 12, 2019, in The Astronomical Journal.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/transients-Candidate-5-DSS-VASCO-Villarroel-et-al-October-17-2025.jpg\" alt=\"Transient flashes: 2 views of the same starfield with a few small white star-like spots visible in one but not the other.\" width=\"800\" height=\"387\" class=\"size-full wp-image-525879\"  \/><a href=\"https:\/\/content.cld.iop.org\/journals\/1538-3873\/137\/10\/104504\/revision1\/paspae0afef11_hr.jpg\" rel=\"noopener nofollow\" target=\"_blank\">View larger<\/a>. | Transient flashes \u2013 momentary light bursts, circled in green \u2013 seen in a digitized <a href=\"https:\/\/www.mariamitchell.org\/astronomical-plates-collection\" rel=\"noopener nofollow\" target=\"_blank\">astronomical plate<\/a> from the Palomar Sky Survey on July 27, 1952. Note that the transients disappear in the 2nd image. Image via Villarroel et al.\/ <a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">Publications of the Astronomical Society of the Pacific<\/a>.<br \/>\nThe 1st transients<\/p>\n<p>Villarroel and her team from the VASCO Network found the first candidate transients in 2016. The researchers analyzed digitized astronomical plates from the <a href=\"https:\/\/skyserver.sdss.org\/dr5\/en\/proj\/advanced\/skysurveys\/poss.asp rel=\" noopener=\"\" target=\"_blank\" rel=\"nofollow noopener\">Palomar Sky Survey<\/a> of star fields from 1949 to 1957. Astronomical plates were an early form of photography that used glass plates to capture images of the night sky. The purpose was to look for any anomalies in the images, such as transient phenomena that flash or suddenly appear or disappear.<\/p>\n<p>In particular, the researchers wanted to see if there were any such anomalies close to Earth. This has been proposed as an alternative to traditional <a href=\"https:\/\/www.seti.org\/research\/seti-101\/seti-research\/\" rel=\"noopener nofollow\" target=\"_blank\">SETI<\/a> (Search for Extraterrestrial Intelligence). SETI\u2019s focus has long been primarily on searching for alien radio signals from distant stars. In more recent years, however, SETI searches have begun to shift to looking for other <a href=\"https:\/\/science.nasa.gov\/universe\/search-for-life\/searching-for-signs-of-intelligent-life-technosignatures\/\" rel=\"noopener nofollow\" target=\"_blank\">technosignatures<\/a> as well.<\/p>\n<p>Now, there are currently 107,875 transients identified that occurred between November 19, 1949, and April 28, 1957. These are noted in the Scientific Reports paper.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/Sputnik-1-satellite-Oct-4-1957.jpg\" alt=\"Shiny metallic ball with four long thin antennas, in space.\" width=\"800\" height=\"655\" class=\"size-full wp-image-366458\"  \/>The closest analogy known so far for the transients on the photographic plates are satellites in <a href=\"https:\/\/en.wikipedia.org\/wiki\/Geosynchronous_orbit\" rel=\"noopener nofollow\" target=\"_blank\">geosynchronous orbit<\/a>. But there\u2019s a catch: the transients were seen in 1949 and the early 1950s, and the 1st satellite, <a href=\"https:\/\/www.nasa.gov\/history\/sputnik\/index.html\" rel=\"noopener nofollow\" target=\"_blank\">Sputnik 1<\/a> (pictured here), wasn\u2019t launched until October 4, 1957. Image via NSSDC\/ NASA\/ <a href=\"https:\/\/en.wikipedia.org\/wiki\/Sputnik_1#\/media\/File:Sputnik_asm.jpg\" target=\"_blank\" rel=\"noopener nofollow\">Wikipedia<\/a>.<br \/>\nObjects near Earth before the 1st satellites?<\/p>\n<p>If you conducted a Palomar Sky Survey today, you would find many short-duration flashes in Earth\u2019s night sky. Most are sunlight reflecting off one of the more than 11,000 active satellites in Earth-orbit. But the images in Villarroel\u2019s studies were obtained before the first satellite, Sputnik 1, was launched on October 4, 1957. The last plate images examined were from April 28, 1957, still several months before Sputnik 1. Villarroel <a href=\"https:\/\/www.su.se\/english\/news\/unexpected-patterns-in-historical-astronomical-observations-1.855042\" rel=\"noopener nofollow\" target=\"_blank\">said<\/a>:<\/p>\n<blockquote>\n<p>Today we know that short flashes of light are often solar reflections from flat, highly reflective objects in orbit around the Earth, such as satellites and space debris. But the photographic plates analyzed in VASCO were taken before humans had satellites in space.<\/p>\n<\/blockquote>\n<p>The transients were identified in publicly-available scanned images from the POSS-I survey available on the <a href=\"https:\/\/archive.stsci.edu\/cgi-bin\/dss_plate_finder\" rel=\"noopener nofollow\" target=\"_blank\">DSS Plate Finder<\/a> website.<\/p>\n<p>If some of the flashes were glints from actual objects, then modeling of the glints suggests that the objects needed to have flat, reflective surfaces. That would mean the objects were likely artificial, which, needless to say, would open a huge can of worms.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/transients-Candidate-1-DSS-VASCO-Villarroel-et-al-October-17-2025.jpg\" alt=\"2 starfields, the same except some white dots appear in the left one that are gone in the other.\" width=\"800\" height=\"401\" class=\"size-full wp-image-525908\"  \/><a href=\"https:\/\/content.cld.iop.org\/journals\/1538-3873\/137\/10\/104504\/revision1\/paspae0afef6_hr.jpg\" rel=\"noopener nofollow\" target=\"_blank\">View larger<\/a>. The Candidate 1 set of transients as seen in a digitized astronomical plate image from the Palomar Observatory. The transients, marked in green circles, appear in the 1st image and disappear in the 2nd image. Spots circled in yellow are defects. The long, white, dashed line shows the alignment of 3 of the transients. Image via Villarroel et al.\/ <a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">Publications of the Astronomical Society of the Pacific<\/a>.<br \/>\nNo transient flashes in Earth\u2019s shadow?<\/p>\n<p>Interestingly, the second study found that there was a dearth of transients in Earth\u2019s shadow. Altogether, about 1\/3 of them were \u201cmissing\u201d in this region of space. This seemed to correlate with the previous research suggesting that these transients might be flashes of sunlight off of reflective objects in high Earth orbits, most likely <a href=\"https:\/\/en.wikipedia.org\/wiki\/Geosynchronous_orbit\" rel=\"noopener nofollow\" target=\"_blank\">geosynchronous orbit<\/a>. A geosynchronous orbit is an Earth-centered orbit that matches Earth\u2019s rotation on its axis. It is 26,199 miles (42,164 km), measured from the center of the Earth. A geosynchronous satellite is at an altitude of approximately 22,236 miles (35,786 km) above mean sea level.<\/p>\n<p>But since this was well before the first satellite launch, what could those objects have been? Villarroel <a href=\"https:\/\/www.su.se\/english\/news\/unexpected-patterns-in-historical-astronomical-observations-1.855042\" rel=\"noopener nofollow\" target=\"_blank\">said<\/a>:<\/p>\n<blockquote>\n<p>Amidst what has been perceived as noise on the plates, there seems to be a genuine population of phenomena that correlate with, among other things, nuclear weapons tests or reports of UAP and that are missing in the Earth\u2019s shadow. You don\u2019t get that kind of solar reflections from round objects like asteroids or dust grains in space, which leave streaks during a 50-minute exposure, but only if something is very flat and very reflective and reflects the sunlight with a short flash.<\/p>\n<\/blockquote>\n<p>Notably, the researchers initially calculated a <a href=\"https:\/\/agilebrandguide.com\/wiki\/statistics\/significance-?-or-sigma\/\" rel=\"noopener nofollow\" target=\"_blank\">21.9 sigma significance level<\/a> for the lack of transients within Earth\u2019s shadow. The sigma significance level is a way scientists express how confident they are that a result is real and not just due to random chance. Upon further refinement of the data, the sigma significance level in these studies was subsequently reduced to a 7.6.<\/p>\n<p>But that is still important, since the \u201cgold standard\u201d confidence level in physics is 5 sigma.<\/p>\n<p>The authors state that this is the biggest argument against the plate defects or contamination explanation. Why would they \u201cavoid\u201d Earth\u2019s shadow?<\/p>\n<p>Connection with nuclear tests?<\/p>\n<p>In the Scientific Reports paper, one of the most interesting findings is the seeming correlation with nuclear tests in the early 1950s. Overall, the researchers found that the transient flashes were 68% more likely to occur the day after a nuclear test on the ground. Co-author <a href=\"https:\/\/www.vumc.org\/painresearch\/person\/stephen-bruehl-phd\" rel=\"noopener nofollow\" target=\"_blank\">Stephen Bruehl<\/a> at Vanderbilt University <a href=\"https:\/\/www.su.se\/english\/news\/unexpected-patterns-in-historical-astronomical-observations-1.855042\" rel=\"noopener nofollow\" target=\"_blank\">said<\/a>:<\/p>\n<blockquote>\n<p>The magnitude of the association between these flashes of light and nuclear tests was surprising, as was the very specific time at which they most often occurred. Namely, the day after a test. What they might represent is a very fascinating question that needs further investigation.<\/p>\n<\/blockquote>\n<p>Does that mean the nuclear tests were the cause of the flashes? One hypothesis has been debris from the explosions lofted into the atmosphere. It\u2019s a possibility, although as the paper <a href=\"https:\/\/www.nature.com\/articles\/s41598-025-21620-3\" rel=\"noopener nofollow\" target=\"_blank\">notes<\/a>:<\/p>\n<blockquote>\n<p>These findings indicate that the chances of observing a transient were 68% higher on the day following a nuclear test compared to days unassociated with nuclear testing.<\/p>\n<p>\u2026 effects in the atmosphere (rather than geosynchronous orbit) would be likely to result in a streak on the image over the 50-minute exposure. Yet all transients appear as distinct point sources rather than streaks. Moreover, this hypothesis is made even more unlikely given that transients were most often observed one day after a nuclear test. Such atmospheric phenomena would have to be sustained and remain localized in one location for approximately 24 hours to account for the visual appearance of transients.<\/p>\n<\/blockquote>\n<p>Transient flashes and UAP sightings<\/p>\n<p>There\u2019s another aspect of the transients that is also intriguing, although more speculative. There were many UAP (UFO) sightings during the late 1940s and early 1950s. Among those were numerous reports of unusual lights or even objects over nuclear facilities. In one case, the researchers found a set of transients in an almost straight line from July 27, 1952. That\u2019s the same night as the famous reports of <a href=\"https:\/\/www.nytimes.com\/1952\/07\/22\/archives\/flying-objects-near-washington-spotted-by-both-pilots-and-radar-air.html\" rel=\"noopener nofollow\" target=\"_blank\">UAP over Washington, D.C.<\/a> Those UAP were both seen visually and tracked on radar.<\/p>\n<p>In regards to UAP in general, the researchers found that the transient flashes increased 8.5% per UAP report. That is, when both the UAP reports and nuclear tests coincided, the effects were additive. Days with both nuclear tests and UAP reports had more than twice as many flashes of light as days without nuclear tests or UAP reports.<\/p>\n<blockquote class=\"bluesky-embed\" data-bluesky-uri=\"at:\/\/did:plc:ujspn5tn56tmudibd2xx2ujf\/app.bsky.feed.post\/3m3s4vzd5o222\" data-bluesky-cid=\"bafyreiany54nnazka5w7cuyk3wimecrn35kcqt2k7nf3lf2cabdixyeava\">\n<p lang=\"en\">A group of astrophysicists (which does not include Avi Loeb) says they have found evidence of unidentified aerial phenomena in old photographic plates dating back to before the time of the first satellites. www.youtube.com\/watch?v=5Gt-\u2026<\/p>\n<p>\u2014 <a href=\"https:\/\/bsky.app\/profile\/did:plc:ujspn5tn56tmudibd2xx2ujf?ref_src=embed\" rel=\"nofollow noopener\" target=\"_blank\">Sabine Hossenfelder (@hossenfelder.bsky.social)<\/a> <a href=\"https:\/\/bsky.app\/profile\/did:plc:ujspn5tn56tmudibd2xx2ujf\/post\/3m3s4vzd5o222?ref_src=embed\" rel=\"nofollow noopener\" target=\"_blank\">2025-10-22T15:10:36.048Z<\/a><\/p>\n<\/blockquote>\n<p>Plate defects and contamination<\/p>\n<p>One issue that critics have raised is the possibility of defects on the photographic plates or other contamination, perhaps even contamination from nuclear fallout particles. The researchers acknowledge this is a problem, but contend that it is more likely, based on their analysis, that the plates could have both defects and genuine anomalies rather than just defects. The paper <a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">says<\/a>:<\/p>\n<blockquote>\n<p>It is scientifically untenable to assume that all candidates are either authentic transients or all defects. A reasonable working assumption is that both populations are present in some unknown proportion. From this perspective, even a single authentic detection among many contaminants would validate the effort and warrant continued search.<\/p>\n<p>Our overall pattern of results is clearly not consistent with the proposition that most transients are due to contamination or defects in photographic plates or scanned images, or to any other local confounds at the observatory itself. Contamination of photographic plates by nuclear fallout produces diffuse fogged spots quite different in appearance than the discrete star-like brightness profiles with point spread functions characteristic of transients.<\/p>\n<\/blockquote>\n<p>Other background objects<\/p>\n<p>The researchers also compared the older images to modern ones to try to rule out other background objects such as stars. The paper <a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">states<\/a>:<\/p>\n<blockquote>\n<p>Rigorous diagnostics with quantitative measurements are central to any search for genuine transients in photographic plates, as overly permissive criteria inevitably admit large amounts of noise. For that reason, we shall use carefully selected transient samples in Solano et al. (2022), which average 167 transients per plate and have been matched to several modern surveys to remove variable stars, asteroids and comets.<\/p>\n<\/blockquote>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/Beatriz-Villarroel-Nordita-Stockholm-University.jpg\" alt=\"Woman with long hair and wearing a long, ornate dress standing with her arms folded.\" width=\"500\" height=\"749\" class=\"size-full wp-image-525911\"  \/><a href=\"http:\/\/beatrizvillarroel.com\" rel=\"noopener nofollow\" target=\"_blank\">Beatriz Villarroel<\/a> at Nordita at Stockholm University in Sweden and <a href=\"http:\/\/www.vascoproject.org\/\" rel=\"noopener nofollow\" target=\"_blank\">The VASCO Network<\/a> is the lead researcher of the investigation into the off transient flashes seen in old astronomical plates from Palomar Observatory from 1949-1957. Image via <a href=\"http:\/\/beatrizvillarroel.com\" rel=\"noopener nofollow\" target=\"_blank\">Beatriz Villarroel<\/a>.<br \/>\nThe origin of the transients remains unknown<\/p>\n<p>The researchers <a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">conclude<\/a>:<\/p>\n<blockquote>\n<p>The origin of the transients remains unknown. One plausible explanation is that they are caused by brief light emissions from artificial objects in orbit or by objects with anomalous movements in Earth\u2019s atmosphere; emissions so brief that they appear as point sources rather than streaks, despite the telescope tracking the stars. Alternatively, they could arise from solar reflections off flat, highly reflective surfaces at geosynchronous altitudes. The latter interpretation is further supported by our shadow test, which reveals a significant deficit of such events within the Earth\u2019s umbra, consistent with a solar reflection origin and difficult to reconcile with many explanations, including photographic plate defects.<\/p>\n<\/blockquote>\n<p>Noted physicist <a href=\"https:\/\/sabinehossenfelder.com\" rel=\"noopener nofollow\" target=\"_blank\">Sabine Hossenfelder<\/a> in Germany has posted an interesting <a href=\"https:\/\/www.youtube.com\/watch?v=5Gt-w38GeNc\" rel=\"noopener nofollow\" target=\"_blank\">video<\/a> about the transients on her YouTube channel. And astrophysicist Adam Frank has some <a href=\"https:\/\/www.everymansuniverse.com\/p\/did-science-just-confirm-1950s-ufo-visits\" rel=\"noopener nofollow\" target=\"_blank\">curious thoughts<\/a> about it. There\u2019s also a <a href=\"https:\/\/phys.org\/news\/2025-10-mysterious-transient-sky-linked-nuclear.html\" rel=\"noopener nofollow\" target=\"_blank\">good new article<\/a> on Phys.org as well. Check them out!<\/p>\n<p>Bottom line: Scientists see mysterious transient flashes of light in 1950s sky images from the Palomar Observatory. It was before the first satellites. What were they?<\/p>\n<p>Sources:<\/p>\n<p><a href=\"https:\/\/www.nature.com\/articles\/s41598-025-21620-3\" rel=\"noopener nofollow\" target=\"_blank\">Transients in the Palomar Observatory Sky Survey (POSS-I) may be associated with nuclear testing and reports of unidentified anomalous phenomena<\/a><\/p>\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1538-3873\/ae0afe\" rel=\"noopener nofollow\" target=\"_blank\">Aligned, Multiple-transient Events in the First Palomar Sky Survey<\/a><\/p>\n<p><a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/1538-3881\/ab570f\" rel=\"noopener nofollow\" target=\"_blank\">The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a \u201cMissing Star\u201d<\/a><\/p>\n<p><a href=\"https:\/\/www.su.se\/english\/news\/unexpected-patterns-in-historical-astronomical-observations-1.855042\" rel=\"noopener nofollow\" target=\"_blank\">Via Stockholm University<\/a><\/p>\n<p><a href=\"https:\/\/earthsky.org\/space\/9-weird-transients-palomar-observatory-1950\/\" rel=\"noopener nofollow\" target=\"_blank\">Read more: 9 weird transients from 1950 still unexplained<\/a><\/p>\n<p><a href=\"https:\/\/earthsky.org\/earth\/uap-and-science-ufos-ualbany\/\" rel=\"noopener nofollow\" target=\"_blank\">Read more: UAP and science: Testing new methods of scientific analysis<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"The 48-inch (1.2 m) Samuel Oschin Telescope at Palomar Observatory. This telescope was used in the 1st Palomar&hellip;\n","protected":false},"author":2,"featured_media":154277,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[270],"tags":[90175,90174,6599,18,50212,19,17,5170,133,451,90173],"class_list":{"0":"post-154276","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-1950s","9":"tag-astronomical-plates","10":"tag-earth","11":"tag-eire","12":"tag-human-world","13":"tag-ie","14":"tag-ireland","15":"tag-palomar-observatory","16":"tag-science","17":"tag-space","18":"tag-transient-flashes"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/115465814529152479","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/154276","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=154276"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/154276\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/154277"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=154276"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=154276"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=154276"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}