That 'interesting' and possibly alien radio signal probably came from our own planet
Earlier this week, astronomers were puzzling over an allegedly powerful burst of energy that seems to have emanated from the star HD 164595, located some 94 light-years away in the constellation Hercules.
"An international team of researchers has announced the detection of 'a strong signal in the direction of HD164595,'" book author Paul Gilster wrote at his blog Centauri Dreams, noting that a Russian radio telescope called RATAN-600 detected the signal on May 15, 2015.
The signal's Russian discoverers urged the Search for Extraterrestrial Intelligence (SETI) to take a long, hard look at HD 164595.
And, as Business Insider previously reported, that's exactly what the organization started doing Sunday night.
"We looked last night with Allen Telescope Array [ATA] last night and didn't find anything," Seth Shostak, a senior astronomer at the SETI Institute who wasn't involved in the signal's initial detection, told Business Insider.
Now an official at the Russian Academy of Science (RAS) has come forward to say the "signal" is anything but alien in origin. In fact, it probably didn't even come from space.
In a statement posted Aug. 30, Yu. V. Sotnikova of the Special Astrophysical Observatory at the RAS wrote that more "processing and analysis of the signal revealed its most probable terrestrial origin."
In other words, it was us.
"It can be said with confidence that no sought-for signal has been detected yet," Sotnikova said.
'Probably not E.T.'
Previously, Shostak said no one was holding their breath in hopes that the signal is alien - not even Claudio Maccone, an Italian astronomer who was working with Russian scientists at RATAN-600 to analyze the signal.
For one, says Shostak, the research group took more than a year to say anything about the signal. "It's a gentlemen's agreement that if you find a signal that could be real, you call up someone else to check it out in an effort to convince yourself," he said. "The people who found it didn't think enough to tell other people right away."
The Russian researchers, Maccone told Shostak, didn't do this because "they were shy."
"To me that says they are not so convinced it's ET [extraterrestrial]," Shostak said, noting that Maccone even told him that he thinks "it is probably not ET."
Second, Shostak says the RATAN-600 radio telescope in Russia (shown above) has a sort of "astigmatism," so it can't verify with great certainty that the signal is actually coming from a place like the HD 164595 star system.
"If you have an ordinary telescope dish, you can zero on one spot on the sky. That spot is usually fairly small, like aiming a laser pointer," Shostak said. "But their antenna is small in one direction and big in another. It's like a squished egg. When you pick something up, you don't know precisely where it's coming from."
Shostak also said the signal the RATAN-600 facility picked up is wide and "spread all over the dial," which makes it harder to verify. "It swallows 1,000 MHz of spectrum. It's like they're getting all of the TV stations at once," Shostak said. "You'd know there's a transmission in there, but not exactly where."
Which is why, when SETI looked for the signal, it may not have found it; it could be spread out and weak in every channel, or powerful in one channel but harder to zero in on.
So what was it?
Business Insider contacted Sotnikova for more details on the probably source of the signal, but did not immediately hear back.
But SETI@Home project scientist Eric Korpela wrote in a forum on the site that it would likely turn out to be something mundane.
"[T]here's really nothing about this 'signal' that would distinguish it from a natural radio transient (stellar flare, active galactic nucleus, microlensing of a background source, etc.) There's also nothing that could distinguish it from a satellite passing through the telescope field of view. All in all, it's relatively uninteresting from a SETI standpoint," Korpela wrote.
"But, of course, it's been announced to the media. ... Someone will look at it with Arecibo, and we'll be along for the ride. ... And we'll all find nothing. It's not our first time at this rodeo, so we know how it works."
The official announcement from the Russian Academy of Science suggests that the initial skepticism was warranted. What could be more mundane than an "alien" signal that's actually coming from Earth?