The Biggest Ever Search for Radio Signals From Alien Civilizations Has Just Been Conducted by Scientists

Scientists from the Breakthrough Listen initiative have conducted the biggest and most sensitive search to date for signals made by potential alien civilizations.

The initiative is a scientific program designed to scour the skies for distant radio and optical signals that could have been produced by extraterrestrial technology—so-called "technosignatures."

Using various telescopes and observatories around the world, Breakthrough Listen has been observing more than 1,700 nearby stars, as well as a wider region of our galaxy's disk, collecting around a petabyte of data in its first three years of operation.

Now, the Breakthrough scientists have submitted their analysis of the majority of this initial data—which also includes information on other objects such as the interstellar asteroid 'Oumuamua—to The Astrophysical Journal while also making it public via their Open Data Archive. This is the largest SETI (search for extraterrestrial intelligence) dataset ever released to the public, equivalent to about 1,600 years of streamed music.

The Breakthrough Listen team, based at Berkeley's SETI Research Center (BSRC) has been using a variety of techniques to look for technosignatures, including advanced algorithms and searches for bright lasers which could be used by alien civilizations to communicate or power spacecraft.

The scientists describe the search for these technosignatures as like looking for a "needle in a haystack," not least because they have to scan through billions of radio signals to find ones which have not been produced by natural processes or human technology.

Using two types of technological "filters," the team whittled down their search to a handful of technosignature candidates. However, on further analysis they found that the remaining signals were in fact man-made, but had managed to evade the filters initially. Nevertheless, the scientists say their observations to date have given them valuable experience for attempting to identify extraterrestrial signals in future searches.

"This data release is a tremendous milestone for the Breakthrough Listen team," Danny Price, lead author of the submitted paper and project scientist, said in a statement. "We scoured thousands of hours of observations of nearby stars, across billions of frequency channels. We found no evidence of artificial signals from beyond Earth, but this doesn't mean there isn't intelligent life out there: we may just not have looked in the right place yet, or peered deep enough to detect faint signals."

The idea behind releasing their vast dataset to the public is to aid astronomical research, not just in the field of SETI but other areas as well.

"While we have been making smaller subsets of data public before in varying forms and contexts, we are excited and proud to offer this first cohesive collection along with an instruction manual, so everybody can dig in and help us search," Matt Lebofsky from BSRC, said in a statement. "And we're just getting started—there's much more to come!"

In fact, Breakthrough Listen wants to survey one million nearby stars, the entire galactic plane and 100 nearby galaxies in total.

Listen is part of a host of "Breakthrough" initiatives—alongside Breakthrough Watch and Breakthrough Starshot—founded by Russian entrepreneur Yuri Milner, all of which are focused on the search for extraterrestrial life.

Parkes Radio Telescope
The Parkes Observatory radio telescope as seen on June 13, 2009 in Australia. Known affectionately as "The Dish," it is one of the largest radio telescopes in the Southern Hemisphere and has been used by Breakthrough Listen scientists in the search for extraterrestrial signals. Lisa Maree Williams/Getty