Since 2007, scientists have been picking up mysterious radio blips, or fast radio bursts (FRBS), that originated somewhere in deep space. Nobody knows what's causing them, but scientists have theories—one of which was dashed to pieces last week.
Last week, Nature published a Cornell-led study that suggests some FRBs are coming from a singular location in space. The landmark finding means that the blips aren't, as was previously thought, each the result of a distinct cosmic event, like a stellar explosion. The Cornell Chronicle explains:
Until now, scientists believed these bursts were isolated, singular events–one-time explosions from the distant corners of the universe…. [but] astronomers now confirm that at least some of these FRB sources emit repeated pulses.
Co-author Shami Chatterjee told the Chronicle that “this research shows for the first time that there can be multiple FRBs from the same place in the sky–with the same pulse dispersion or distance,” adding, “Whatever produces the FRB can’t be destroyed by the burst, because otherwise, what would produce the next pulse?”
Some have floated the idea that the source of this type of signal might be intelligent extraterrestrial life. Last year, researchers mapped out the FRBs known to scientists at the time and found them to be weirdly symmetrically distributed. New Scientist explained at the time why some thought that might be a case for alien communication:
The most tantalising possibility is that the source of the bursts might be a who, not a what. If none of the natural explanations pan out, their paper concludes, “An artificial source (human or non-human) must be considered.”
Jill Tarter, who once served as director of the SETI Institute, told New Scientist that FRBs "have been intriguing as an engineered signal, or evidence of extraterrestrial technology, since the first was discovered."
But scientists aren't jumping to the conclusion that these bursts are coming from aliens. The Cornell researchers suggest that faraway neutron stars are likely the source of these FRBs. Co-author James Cordes said that "we’re detecting these FRBs from very far away, which means that they are intrinsically very bright. Only a few astrophysical sources can produce bursts like this."
That doesn't mean that FRBs don't occur often. Christian Science Monitor explains:
Every day, an estimated 10,000 FRBs flash across the sky. In their brief, millisecond-long appearance, they release as much sun as the sun emits in 10,000 years. But their short duration and unpredictable arrival makes observing them a challenge.
Difficulty detecting the signals has led to controversy over what, exactly, is going on. Nature noted last week that two papers on FRBs published close together were contradictory. Per Nature:
On 24 February, astronomers announced that they had identified the origin of an FRB in a galaxy 1.9 billion parsecs (6 billion light years) away, probably produced by a collision between two neutron stars… But two days later, astronomers Edo Berger and Peter Williams argued in a paper posted on the preprint server arXiv that the afterglow could, in theory, have come from a periodic radio-wave flare-up at the galaxy’s core, where matter spirals into a supermassive black hole.
New, powerful telescopes (slated to start operating this year) could make it easier to detect FRBs and draw conclusions about their origins.
So probably don't plan on getting intergalactic messages from smart aliens. But you never know. The truth is out there.
Danielle Wiener-Bronner is a news reporter.