Light signals from 2.5 million stars observed by the Sloan Digital Sky Survey have been analyzed by astronomers, who have identified unusual ‘strobe-like’ blasts from 234 stars.
The only report on these light pulses given by astronomers Ermanno Borra and Eric Trottier from Laval University in Canada was that they “have exactly the shape of an Extra-Terrestrial Intelligence signal.” An alien-hunting mission led by Stephen Hawking’s was set up to clarify the matter.
So far, scientists from the Breakthrough Listen project – funded by Stephen Hawking and Russian billionaire Yuri Milner, and run by the SETI (Search for Extraterrestrial Intelligence) Research Centre at the University of California Berkeley, are rather skeptical that 234 extra-terrestrial civilizations are beaming a coordinated light signal towards Earth. The claim is not only premature, but, it hasn’t been formally peer-reviewed yet, nor has replication of the results been attempted by an independent research team.
The statement the SETI Research Centre released last week read: “The one in 10,000 objects with unusual spectra seen by Borra and Trottier are certainly worthy of additional study. However, extraordinary claims require extraordinary evidence. It is too early to unequivocally attribute these purported signals to the activities of extraterrestrial civilizations.”
As to what the duo of Canadian researchers discovered, it all goes back to 2012, when Borra had suggested that the only logical way of communication that an extraterrestrial civilization would use to contact us was laser pulses that look unnatural enough for investigation.
According to Borra, the kind of energy needed to blast such a signal towards Earth from another galactic place “is not crazy.” What Borra did was join forces with Trottier to scrutinize the 2.5 million stars recorded by the Sloan Digital Sky Survey and find out whether any of them have produced such a signal.
The research duo has now reported that not one, but 234 stars have produced the exact signal they were looking for.
Their conclusion in a paper on pre-print website, arXiv.org, reads “We find that the detected signals have exactly the shape of an ETI (Extra-Terrestrial Intelligence) signal predicted in the previous publication and are therefore in agreement with this hypothesis.”
These findings have been the subject of much criticism in scientific circles for a number of reasons. For one thing, if aliens are excluded from the occurrence, as Hall explains for New Scientist, what the Canadian researchers found was that the vast majority of the 2.5 million stars belong to the same spectral class as the Sun; however, 234 of them are sending beam pulses of the same periodicity, approximately 1.65 picoseconds, towards Earth. This leaves fair grounds for suspicion that it could be human or software error in data calibration or analysis.
According to Andrew Siemion, director of the SETI Research Centre at Berkeley, “There is perhaps no bolder claim that one could make in observational astrophysics than the discovery of intelligent life beyond the Earth.”
“It’s an incredibly profound subject – and of course that’s why many of us devote our lives to the field and put so much energy into trying to answer these questions. But you can’t make such definitive statements about detections unless you’ve exhausted every possible means of follow-up.”
This is the major reason why the SETI Research Centre and the Breakthrough Listen project have decided to join in. According to them, there are already internationally established protocols on finding evidence of extraterrestrial life. These include independent verification using two or more telescopes, and “careful work” to define false positive rates and eliminate all other explanations.
For the purpose of the research, they have even set up a 0-10 scale, called the Rio Scale, which will measure findings of phenomena that may point to the existence of advanced extraterrestrial life.
According to them, the Borra-Trottier result is currently a 0 or 1 (“None/Insignificant”) on the Rio scale.
The announcement given last week stated “The Berkeley SETI Research Centre team has added several stars from the Borra and Trottier sample to the Breakthrough Listen observing queue on the 2.4-metre Automated Planet Finder (APF) optical telescope.”
“The capabilities of the APF spectrograph are well matched to those of the original detection, and these independent follow-up observations will enable us to verify or refute the reported detections.”