The killjoys at the SETI Institute -- killjoys all over the world, really -- are damping down wild speculation that a Russian instrument has seen a “possible” alien transmission.
Right now, as it happens, nobody knows what was spotted by the RATAN-600 telescope in Russia, partly because its operators kept the observation under their hats for more than a year, and partly because it hasn't been repeated.
Hence even though a signal in the 2.7 cm wavelength (11 GHz band) was spotted for four seconds on May 15, 2015, the SETI Institute's Seth Shostak only goes as far as to say the signal is “interesting”.
Shostak agrees that the signal appears to originate from star system HD164595, if the interpretation of the RATAN-600 observation is correct; but with no second observation to draw on, we can't even guarantee its origin isn't Earth.
Astrophysicist Katie Mack (@AstroKatie), a postdoctoral research fellow at Melbourne University, explained to Vulture South that “there are tons of things that can cause a blip” that a radio telescope picks up.
Mack pointed The Register to this post by SETI@Home's Eric Korpela, who identifies flares, microlensing events as processes that can cause a brief spike, and adds that it could feasibly be “interference from a passing satellite”.
Mack wrote in an e-mail to us that “It doesn’t even look like terrestrial interference has been ruled out — sometimes something as simple as a spark from a power line can cause radio interference that can mess with telescopes. With only one blip like this, seen by one telescope, it’s really impossible to know what it might have come from.”
Hence both Korpela and Shostak agree that more observations are needed, merely to make a starting point. The SETI Institute has pointed the Allen Telescope Array in the direction of HD164595, but it needs several observations to cover all the frequencies received by the very broadband RATAN-600 (1 GHz bandwidth is “a billion times” the bandwidth typical SETI searches use).
Shostak adds “The discoverers didn’t alert the SETI community to this find until now, which is not as expected. According to both practice and protocol, if a signal seems to be of deliberate and extraterrestrial origin, one of the first things to do is to get others to attempt confirming observations. That was not done in this case.”
Mack told The Register unexpected signals are a common occurrence, and so far haven't needed extra-terrestrials to explain them:
“It’s not uncommon in astronomy to see a signal we don’t understand, but so far, after lots of data gathering, everything has turned out to be some cool new astrophysical process,” she wrote.
“If we jumped to 'maybe it’s aliens!'” every time, we’d have a lot of trouble just getting through the science and figuring it out. This blip doesn’t look like a particularly compelling candidate for a SETI signal, being such an isolated unconfirmed event, so it’s kind of odd that it’s getting so much media attention.”
The Register would add that it'd be just as good, or better, if the HD164595 signal – if it exists – turned out to be a “cool new process”. ®