The science community was all abuzz over the weekend after some tantalizing (though far from definitive) news came out from the folks at SETI, or the Search for Extraterrestrial Intelligence. Theyve been processing a signal that they received in 2019 and it’s made its way through their many layers of “filters,” remaining categorized as something they can’t quite explain away as the random background noise of the universe or misidentified human broadcasts. In fact, their “most likely” explanation, at least so far, is that it’s a signal that was produced by “technology.” And it’s coming from one of our closest galactic neighbors. (The Debrief)
A team of researchers from the Breakthrough Listen project have detected a mystery signal coming from Proxima Centauri, our closest cosmic neighbor. This latest detection was captured in 2019 and, after confirming the signal, researchers are now considering some unlikely causes, even alien ones.
“It is very exciting when possible signals come in,” stated astrobiologist Dr. Jacob Haqq-Misra, a senior researcher with the Blue Marble Space Institute of Science told The Debrief. “SETI is a ‘needle in a haystack’ game after all, so unusual technosignature candidates like this draw a lot of interest.
At this point, much more research is needed to confirm the precise nature of the signal and its possible causes. However, Dr. Andrew Siemion from the University of California, Berkeley, and the project’s principal investigator freely admits why this discovery has already become such a huge story. “The reason we’re so excited about SETI [the Search for Extraterrestrial Intelligence], and why we dedicate our careers to it, is the same reason why the public gets so excited about it. Its aliens! It’s awesome!”
It’s definitely too soon to flatly declare that ET is phoning home, but based on the description, the signal is definitely intriguing for a few reasons. Scientific American provides a few more of the details, as well as a cautionary note about not getting our hopes up too much just yet. The signal was transmitted at 982 megahertz, which is not a frequency that humans are making much use of. Also, it’s packed into a very tidy “single bin in frequency” rather than the scattershot radiation and noise generated by stars, black holes, and everything else out there in the void. But they also can’t rule out that it might be coming from some “exotic quirk of plasma physics.”
Another curious aspect of this signal is that while the frequency band is quite tight, it does not appear to contain any encoded data that they’ve been able to detect. It’s rather like an unmodulated carrier wave from a radio antenna. There’s a transmission, but no audio, video or other data is embedded in it. Of course, we can’t assume that anyone in the universe would have to decide to modulate radio waves the same way we do, either.
For now, these scientists maintain that the only identifiable source for something like this would be “technological” in nature. But it could still turn out to be some type of natural phenomenon that we haven’t previously identified. More study will be required.
The other exciting thing about this discovery is that the signal is coming from our nearest cosmic neighbor, Proxima Centauri, 4.2 light-years from the Earth. That’s still an unimaginable distance in strictly human terms, but it’s only a stone’s throw away on the galactic scale. Also, we already know that Proxima Centauri has at least two planets orbiting it, one of which (Proxima b) is in the star’s “Goldilocks zone” where the temperature is in the range to allow liquid water on the surface of a rocky world like ours. Further, Proxima b is only 1.2 times the mass of the Earth, so the gravity on the surface wouldn’t be that much greater than ours.
Most astrophysicists caution us about the fact that Proxima Centauri is a red dwarf. That means that it’s less stable than our own yellow star and its habitable zone is much closer to the star. This has led to a general belief that such planets would be less hospitable to life as we know it. But if somebody is broadcasting a transmission from there, who can really say? It’s far from a given at this point, but it’s one of the most exciting bits of news to come out of SETI in a very long time.