In 2010, Emily Petroff and her colleagues at the Parkes Observatory in Australia had a problem. They were conducting a systematic search for Fast Radio Bursts (FRBs)—those brief, intense pulses of radio energy that appear to come from distant galaxies. But their data was contaminated by anomalous signals. Specifically, they kept recording bursts that seemed to originate from everywhere and nowhere simultaneously, appearing in all receiver channels at once, regardless of sky direction.
These "perytons"—named after a legendary winged creature from medieval bestiaries—were supposed to be something strange. Possibly exploding stars. Possibly collapsing stellar remnants. Possibly signals from distant civilizations, reflected or distorted in ways that made their sources untraceable.
For four years, they remained an unsolved puzzle. Then, in 2015, Petroff and her team finally figured out what the perytons actually were.
They were the Parkes Observatory's microwave oven.
The Perfect Scientific Embarrassment
The story is almost too perfectly timed to be real. Late afternoon, just before the evening shift at Parkes Observatory. Someone opens the microwave oven before it's finished heating. The resulting electromagnetic interference spills out across the radio frequencies the telescope monitors, creating a signature that looks—to the untrained analysis algorithms—exactly like a signal from space.
The burst appears in all receiver channels because the interference is local, not from the sky. It's isotropic, arriving from every direction at once. It's brief, energetic, and completely consistent with an actual Fast Radio Burst if you don't know where to look.
What makes the peryton story even more delightful is that for years, astronomers didn't know where to look. The signal was so consistent that some researchers genuinely wondered if it might be evidence of some exotic astrophysical phenomenon unknown to science. Dozens of papers proposed mechanisms. The peryton became a small mystery in the SETI community, discussed and debated in the serious literature.
And then someone noticed the correlation. Every time a peryton appeared, someone had just used the observatory's microwave oven. The signal disappeared once they installed a proper microwave with proper shielding.
What Perytons Taught Us About Science
The peryton story has become a famous (and slightly embarrassing) parable in astronomy. It demonstrates several crucial scientific principles:
First: Extraordinary claims require extraordinary evidence, and even then, the mundane explanation should be ruled out first. Astronomers didn't assume perytons were supernatural or alien. They conducted systematic investigations. But they also didn't immediately consider the most obvious local source because the signal seemed to have characteristics inconsistent with Earthbound interference.
Second: Technology shapes what we can observe. Parkes Observatory's design and sensitivity made it vulnerable to microwave oven interference in a way that other telescopes might not be. The discovery of perytons led to better shielding, which led to cleaner data and better science overall.
Third: Science is human, and humans make mistakes. This isn't a failure of the scientific method—it's a success. The method allows for contamination to be identified and corrected. The peryton episode could have been covered up or explained away. Instead, it was published and analyzed, and the solution was shared with the broader community.
The Irony Is Perfect
Here's what makes the peryton story genuinely beautiful: in trying to detect one of the most exotic astrophysical phenomena known—transient radio bursts from the distant universe—astronomers were stymied by the most mundane laboratory equipment imaginable. A microwave oven.
It's the kind of irony that appears in fiction and feels too convenient to be real. But it happened. And it's worth remembering the next time you read a story about astronomers detecting something "mysterious" or "unexplained."
The lesson is not that astronomers are careless. The Parkes team was meticulous. The lesson is that nature is subtle, our instruments are sensitive, and sometimes the hardest signal to identify is the one coming from your own observatory.
The Brighter Side
The peryton story also has a positive epilogue. The work to identify perytons led to better understanding of Parkes Observatory's instrumentation and how to shield it from terrestrial interference. This made the observatory a better, more reliable tool for genuine astrophysical discovery.
Moreover, the investigation accelerated the global understanding of Fast Radio Bursts. While the perytons themselves were false alarms, the experience of studying and classifying them refined the methods astronomers use to distinguish real cosmic signals from local noise. By 2015, when Petroff et al. finally published the peryton resolution, the FRB field had matured significantly. Real FRBs were being discovered and systematically studied. The false positives had been eliminated.
The subsequent discovery that at least some FRBs come from magnetars—the neutron star-like objects that emit intense magnetic fields—came from this more refined, better-shielded apparatus. The perytons, in their way, contributed to genuine discovery by being false alarms that forced improvements.
Myth vs. Reality
Myth: Perytons were somehow a coverup or a conspiracy. Reality: The Parkes team publicly investigated the signals, collaborated with other astronomers, and published the resolution. The process was transparent and scientific.
Myth: Scientists should have known immediately they were local interference. Reality: The signals had characteristics that, without systematic analysis across multiple instruments and time periods, genuinely resembled cosmic transients. Identifying terrestrial interference requires patience and systematic comparison.
Myth: The peryton story means SETI should be skeptical of all signals. Reality: The story actually supports systematic SETI methodology: careful observation, independent confirmation, and rigorous analysis of mundane alternatives. The system worked.
Where Things Stand Now
The Parkes Observatory continues to be one of the world's leading facilities for transient astrophysics. With better shielding and more refined analysis methods, it's helped discover genuine Fast Radio Bursts and contributed to understanding their origins. The peryton episode is now taught in astronomy courses as a cautionary tale and a tribute to scientific self-correction.
Emily Petroff has gone on to lead research on Fast Radio Bursts globally, contributing significantly to the understanding of these genuinely mysterious phenomena. And the microwave oven at Parkes Observatory has become a minor celebrity in the annals of science, a reminder that every tool—even the smallest, most mundane piece of equipment—can affect what we observe of the universe.
The peryton story is a gift to science communicators. It shows that mystery is real, that investigation is rigorous, and that sometimes the answer to a cosmic puzzle is sitting in the break room. It's a reminder that science is both the search for profound truths and the messy, sometimes humbling process of ruling out what it's not.
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Sources
- Burke-Spolaor et al. (2011), "Radio transients from stellar tidal disruption by massive black holes," MNRAS
- Petroff et al. (2015), "Identifying the source of perytons at the Parkes Observatory," MNRAS
- Parkes Observatory archival records