SCOTT SIMON, HOST:
Astronomers have a mystery on their hands. Two large radio telescopes have detected very brief, very powerful bursts of radio waves. They can't tell where the bursts are coming from or what's causing them. And as NPR's Joe Palca reports, astronomers do not rule out any explanations, even the kind of outrageous claims you'd expect to see in a science fiction novel.
JOE PALCA, BYLINE: The first report of these so-called fast radio bursts appeared in 2007. Duncan Lorimer and his colleagues had found the signal buried in recordings made at the Parkes radio telescope in Australia. Lorimer argued at the time that the source of the burst was from way, way beyond our galaxy. But then the same telescope recorded a bunch more bursts that were similar but clearly coming from something much closer by.
DUNCAN LORIMER: They cast a lot of doubts on the original detection that we may.
PALCA: Something nearby would probably have a much more pedestrian explanation. Other astronomers began to suspect Lorimer's extra-galactic detection was a fluke. But that changed last year.
LORIMER: 2013, there came a big paper in Science announcing the discovery of four more.
PALCA: That 2013 Science paper convinced most astronomers that something real, far away and still very mysterious was happening. But there was one lingering doubt. All of the detections were made by one radio telescope - the Parkes telescope in Australia. So some astronomers wondered if the burst might not be an astronomical event at all but some problem with the electronics in the telescope.
LORIMER: It's clearly not.
PALCA: That's because now there's a report of a burst detected at the Arecibo radio telescope in Puerto Rico. Lorimer says that several more reports of detections will soon be showing up in the scientific literature. As you would imagine, there's been lots of speculation about what's behind these mysterious bursts. Some astronomers think they're caused by blitzars. These aren't Santa's reindeer but a pulse of energy from a supermassive star collapsing into a black hole. Others think they may be caused by powerful solar flares coming from stars nearby.
LORIMER: There've even been discussions in the literature about signatures from extraterrestrial civilizations.
LORIMER: I had to mention it, didn't I?
PALCA: It's just a theoretical paper, suggesting the bursts could be generated by intelligent beings intentionally beaming a radio signal directly at Earth.
JAMES CORDES: I would bet against it.
PALCA: That's James Cordes. He's an astronomer at Cornell University who's also in the hunt for an explanation of these radio bursts. Cordes says astronomers will need to find more examples of these bursts before they'll be able to say with any certainty what's causing them. But finding them will take time. The kinds of radio telescopes that can detect these bursts have what Cordes calls tunnel vision.
CORDES: We don't see the whole sky. We see just a very narrow snippet of it.
PALCA: So catching a burst in the act requires a bit of luck. Of course that's frustrating for astronomers. But having only a tiny bit of hard data does have its upside. It means theoreticians can spin out all kinds of interesting ideas.
CORDES: The nice thing about this in the current stage is that we really don't know what these bursts are caused by. And so the sky is the limit in some respects.
PALCA: I'm tempted to make a comment about an astronomer using the phrase the sky is the limit. But I think I'll let that pass. Joe Palca, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.