May 21, 2022 07:24 PM
https://www.inverse.com/science/alien-cr...old-photos
EXCERPTS: On a series of 70-year-old photographic plates containing images of the night sky, a few astronomers say they’ve found something weird: flashes of light that appear and then disappear, like ghosts.
“We found one image where nine stars were out there, and they vanished. And they are not there half an hour earlier, and they are not there six days later,” says Beatriz Villarroel, a postdoctoral researcher at the Nordic Institute for Theoretical Physics. “And you wonder, ‘Is this real?’”
There isn’t any readily available astronomical explanation for what these vanishing points of light, which the researchers call transients, might be. The dots might be defects in the photographic emulsions or image artifacts from when astronomers first scanned the plates. But in a series of recent papers, Villarroel and a small team of astronomers have been more seriously probing the possibility that the flashes might be something more exciting — extraterrestrial objects.
A shiny, spinning object passing by Earth would leave a line of dots in a long-exposure image of the night sky. Asteroids or meteors aren’t likely to look like that — most asteroids are dark, and meteors are moving so fast they’d look like streaks. And, most intriguingly for the researchers, there weren’t any satellites in the night sky when the images were taken, as all the plates were before the launch of Sputnik.
Still, Villarroel and colleagues haven’t ruled out Earthly explanations for these tantalizing dots. And there’s a long history of events associated with the search for extraterrestrial intelligence (SETI) fizzling out under closer scrutiny.
[...] In a paper published in Scientific Reports in 2021, the scientists take a closer look at the nine transients to see if they could find a more ordinary explanation for them. They ruled out astrophysical explanations, passing airplanes, asteroids, and other known light sources. The dots could have come from contamination caused by nuclear fallout, they say — it was the era of nuclear experimentation, after all. But no known tests happened in 1950. Villarroel and her colleagues hint that that leaves the door open to other explanations. Like, say, extraterrestrial spacecraft.
Wanting to believe — In two subsequent papers, the researchers take that idea more seriously. In a paper in Acta Astronautica published in 2022, they explore ways to find similar instances of transients in other images, laying the groundwork for future research. And in a paper published in 2022 to the pre-print server the arXiv (meaning it hasn’t been peer-reviewed yet), the researchers detail other instances of transient flashes of light that seem to line up.
Villarroel isn’t saying it’s aliens, of course. “We are very careful when we write our papers, because we are not sure if they are real or not,” she says. “We need to always assume that it is the most boring explanation.”
There are some good reasons to suspect the explanation is indeed more boring, says Paul Horowitz, an emeritus professor of physics and electrical engineering at Harvard and a member of the ET-hunting PANOSETI project, who was not involved in the study.
He used the Palomar plates earlier in his career, he says, and the presence of odd flashes of light doesn’t surprise him. “There would be these things that we’d call Kodak stars, which were basically blemishes in the emulsion,” Horowitz says. “Film is full of that kind of stuff. If you look at enough of these, and there’s a lot of them, you’re going to find artifacts.”
He also points out that the object, if there was one, needn’t be in geosynchronous orbit, as Villarroel and her coauthors suggest. Depending on how often it flashes and how long the flashes are, an object could appear as a series of dots in a long exposure at a range of distances, from within Earth’s atmosphere to far beyond our planet. That could mean whatever’s on the plates could also be something launched from Earth... (MORE - missing details)
EXCERPTS: On a series of 70-year-old photographic plates containing images of the night sky, a few astronomers say they’ve found something weird: flashes of light that appear and then disappear, like ghosts.
“We found one image where nine stars were out there, and they vanished. And they are not there half an hour earlier, and they are not there six days later,” says Beatriz Villarroel, a postdoctoral researcher at the Nordic Institute for Theoretical Physics. “And you wonder, ‘Is this real?’”
There isn’t any readily available astronomical explanation for what these vanishing points of light, which the researchers call transients, might be. The dots might be defects in the photographic emulsions or image artifacts from when astronomers first scanned the plates. But in a series of recent papers, Villarroel and a small team of astronomers have been more seriously probing the possibility that the flashes might be something more exciting — extraterrestrial objects.
A shiny, spinning object passing by Earth would leave a line of dots in a long-exposure image of the night sky. Asteroids or meteors aren’t likely to look like that — most asteroids are dark, and meteors are moving so fast they’d look like streaks. And, most intriguingly for the researchers, there weren’t any satellites in the night sky when the images were taken, as all the plates were before the launch of Sputnik.
Still, Villarroel and colleagues haven’t ruled out Earthly explanations for these tantalizing dots. And there’s a long history of events associated with the search for extraterrestrial intelligence (SETI) fizzling out under closer scrutiny.
[...] In a paper published in Scientific Reports in 2021, the scientists take a closer look at the nine transients to see if they could find a more ordinary explanation for them. They ruled out astrophysical explanations, passing airplanes, asteroids, and other known light sources. The dots could have come from contamination caused by nuclear fallout, they say — it was the era of nuclear experimentation, after all. But no known tests happened in 1950. Villarroel and her colleagues hint that that leaves the door open to other explanations. Like, say, extraterrestrial spacecraft.
Wanting to believe — In two subsequent papers, the researchers take that idea more seriously. In a paper in Acta Astronautica published in 2022, they explore ways to find similar instances of transients in other images, laying the groundwork for future research. And in a paper published in 2022 to the pre-print server the arXiv (meaning it hasn’t been peer-reviewed yet), the researchers detail other instances of transient flashes of light that seem to line up.
Villarroel isn’t saying it’s aliens, of course. “We are very careful when we write our papers, because we are not sure if they are real or not,” she says. “We need to always assume that it is the most boring explanation.”
There are some good reasons to suspect the explanation is indeed more boring, says Paul Horowitz, an emeritus professor of physics and electrical engineering at Harvard and a member of the ET-hunting PANOSETI project, who was not involved in the study.
He used the Palomar plates earlier in his career, he says, and the presence of odd flashes of light doesn’t surprise him. “There would be these things that we’d call Kodak stars, which were basically blemishes in the emulsion,” Horowitz says. “Film is full of that kind of stuff. If you look at enough of these, and there’s a lot of them, you’re going to find artifacts.”
He also points out that the object, if there was one, needn’t be in geosynchronous orbit, as Villarroel and her coauthors suggest. Depending on how often it flashes and how long the flashes are, an object could appear as a series of dots in a long exposure at a range of distances, from within Earth’s atmosphere to far beyond our planet. That could mean whatever’s on the plates could also be something launched from Earth... (MORE - missing details)