Some radio signals called "perytons" detected at the Parkes and Bleien Radio Observatories seemed to be coming from deep space, but they had some interesting characteristics.
They were short, only 25 had been reported and they seemed to only happen during the weekday in office hours. Hmm.
Australian scientists investigated further.
Though the peryton might have some similarities to fast radio bursts, which are of "extragalatic origin," scientists said the origin of the peryton "remained a mystery" — until now.
"We have identified strong out-of-band emission at 2.3--2.5 GHz associated with several peryton events. Subsequent tests revealed that a peryton can be generated at 1.4 GHz when a microwave oven door is opened prematurely and the telescope is at an appropriate relative angle," Emily Petroff and her colleagues wrote in the study abstract. "Radio emission escaping from microwave ovens during the magnetron shut-down phase neatly explain all of the observed properties of the peryton signals."
Petroff told National Geographic "it was quite surprising that it ended up being microwaves."
This discovery allowed the scientists to "demonstrate that the microwaves on site could not have caused FRB 010724." Earlier this year, Petroff and her colleagues described observing what they think is the first fast radio burst detected live.
She told Fox News at the time that the source was "probably not aliens" and they were "confident that they’re coming from natural sources."
With these more recent findings, the researchers said they have clues that will further differentiate true fast radio bursts from perytons:
- This and other distinct observational differences show that FRBs are excellent candidates for genuine extragalactic transients.
- A direct test of “peryton vs. FRB” can be made via the detection or non-detection, respectively, of concurrent 2.3–2.5 GHz emission.
"We have thus demonstrated through strong evidence that perytons and FRBs arise from disparate origins," Petroff et al. wrote. "There is furthermore strong evidence that FRBs are in fact of astronomical origin."
The complete origin of FRBs though still remains unexplained.
Front page image via Shutterstock.