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Space fans hoping that comet 3I/ATLAS, an intruder from beyond our solar system, was actually an alien spacecraft, may be disappointed by new research that could put an end to that speculation once and for all.
astronomers use green bank telescopeemployed by breakthrough listening Extraterrestrial Signal Search Astronomy Project, Search 3I/Atlas Measurable signs of technology from extraterrestrial civilizations, or “Technical signature“.
Although the search turned up nothing, in fact 3I/ATLAS is only the third known object discovered since entering the solar system from interstellar space (the others are 1I/’Oumuamuaseen in 2017, and 2I/Borisovdetected in 2019) means it remains a fascinating object despite its natural origin.
“We would all be excited if we found technical signatures from 3I/ATLAS, but they just aren’t there,” lead researcher Benjamin Jacobson-Bell of the University of California, Berkeley, told Space.com. “Not finding any signals is what we would expect because there is a lot of evidence that 3I/ATLAS is a comet with only natural signatures.
“The evidence suggests that 3I/ATLAS is not such a detector, but we would be remiss if we did not check it.”
Jacobson-Bell explains that scientists have even discussed using our own detectors to conduct such precise explorations. An example of this is Groundbreaking Starshot Projecta concept that proposes launching thousands of extremely light detectors Alpha Centaurithe closest star system to our sun.
Jacobson-Bell added: “There are compelling reasons to think that spacefaring species would send probes to other star systems to learn more about their stellar neighbors.”
Listen to Radio 3I/ATLAS
The team behind this study speculates that the brightest alien technology signatures, if we find them, are likely to be narrowband radio signals, since these signals require relatively little energy to generate and can travel long distances.
“Breakthrough Listen searches for life beyond Earth in a number of ways. The Green Bank Telescope is a 100-meter-wide radio antenna located in a federally regulated area free from most radio interference,” said Jacobson-Bell. “Its sensitivity allows us to verify the presence of transmitters as low as 0.1 watts, which is the strongest evidence to date of any 3I/ATLAS observing technology.”
By comparison, modern cell phones typically emit radio waves at levels around 1 watt.
“That said, if there were transmitters on 3I/ATLAS that were ten times weaker than a cell phone, we would be able to find them,” Jacobson-Bell continued.
Comet 3I/ATLAS passes through the solar system. |Image credit: Miquel Serra-Ricart/Light Bridges
“Humans generate a large number of narrowband radio signals, including those used to communicate with our own spacecraft,” Jacobson-Bell said. “However, by modeling our search strategy based on human technology output, we ended up detecting a large number of man-made signals! We therefore pass any detections through filters to distinguish possible man-made interference from possible extraterrestrial signals.”
The Green Bank telescope covers a very wide range of radio frequencies, meaning the team is unlikely to have missed any signals purely because they observed the wrong part. electromagnetic spectrum.
“We did find nine ‘events,’ which is our term for signals that passed certain filters in our search strategy, but upon closer inspection we could easily attribute all nine to known radio transmitters on Earth,” Jacobson-Bell said. It’s common to find and then discard false positives like this.
“Past work has shown that 3I/ATLAS looks like a comet and behaves like a comet, and our observations show that, like a comet, 3I/ATLAS is not the source of the technological signal. Ultimately, there are no surprises.”
As Jacobson-Bell points out, this may be a bit disappointing, but it doesn’t mean that 3I/ATLAS is no longer of huge scientific interest.
“3I/ATLAS has generated considerable excitement because it is the third discovery of an interstellar object in our solar system,” he continued. “Sending spacecraft to other star systems could be very informative, so it’s easy to imagine that some interstellar objects could be intentional probes.”
Comet 3I/ATLAS cuts through a dense star field in this image taken with the Gemini Multi-Object Spectrograph (GMOS) at Gemini South in Monte Passon, Chile. The colored stripes are the stars in the background of the image. |Image source: International Gemini Observatory/NOIRLab/NSF/AURA/Shadow the ScientistImage processing: J. Miller & M. Rodriguez (International Gemini Observatory/NSF NOIRLab), TA Rector (University of Alaska Anchorage/NSF NOIRLab), M. Zamani (NSF NOIRLab)
Jacobson-Bell believes that with the recently completed discoveries of interstellar objects it may become more common Vera Rubin Observatory begins its 10-year Heritage Space-Time Survey (LSST).
“While every individual interstellar object is currently an anomaly, future surveys will aggregate so many interstellar objects that we will begin to be able to discern which ones are typical and which ones are actually anomalous,” he said. “Some of these objects deserve follow-up observation — are their anomalies caused by technology?”
Therefore, this new study and its findings on 3I/ATLAS paves the way to answer this question.
“We hope that our search will help dispel the idea that this object is man-made, but equally we hope that public interest in interstellar objects remains strong – whether they are spacecraft or comets, they are all very interesting, and it is entirely possible that one day one of them will indeed be transmitting a technological signal,” Jacobson-Bell concluded. “If we don’t look, we’ll never know.”
The team’s research is available as a peer-reviewed paper on the repository’s website arXiv.
