In March 2015, astronomers at Parkes Observatory in Australia were trying to identify the source of radio signals picked up at the observatory and came up with a surprising discovery.
The signals were called perytons, a type of radio signal resembling fast radio bursts (FRB) that came from somewhere else outside the galaxy billions of light years away. But these new mysterious radio signals were different, and their origins were unknown. These unknown signals were named perytons in 2011 and named after a mythical, fictional animal from the Book of Imaginary Beings by Jorge Luis Borges.
A total of 46 Perytons had been observed at the Parkes Observatory from 1998 to 2015, and scientists thought that might have a terrestrial origin, specifically lightning strikes. In 2015, they installed a new receiver and were able to track the source. The result was surprising as the signals ended up being caused because of the inadvertent opening of a microwave oven in the break room on the site of the observatory.
Tests revealed that a peryton could be generated at 1.4 GHz when a microwave oven door was opened before the timer went off. The researchers also discovered that the telescope had to be at an appropriate relative angle to the microwave to pick up the peryton.
In short, when the telescope was at just the right angle and the microwave oven door was opened, the oven gave off a short but strong radio signal that was picked up by the telescope. This signal resembled an FRB but was close in origin as opposed to where fast radio bursts were believed to originate from. The researchers also noted that the perytons occurred on weekdays and during office hours.
The two microwave ovens responsible for these mysterious signals were both manufactured by Matsushita/National and were more than 27 years old. The magnetron in the ovens was the ultimate source, but the door had to be open before the timer finished. Though this proved perytons and fast radio bursts were different than each other, it was concluded that the first FRB discovered at the observatory by the telescope in 2007, and the first FRB ever discovered, was not caused by the microwave ovens.
Fast radio bursts are important in the field of astrophysics as they are incredibly powerful, giving off as much energy in a millisecond as the Sun does after many days. Though it is not known how they are produced, they allow scientists to learn about the matter the radio bursts pass through on their way to Earth.
As the burst of radio waves travel, they disperse or spread out. By knowing this, researchers can determine how far apart things are. Radio waves that arrive at a telescope with a higher frequency arrive sooner than those at lower frequencies, indicating they haven’t dispersed as much and came from somewhere closer.
Astronomers know these bursts come from outside our galaxy, and one such FRB was found to originate from a galaxy 3 billion light-years from Earth. These fast radio bursts help astronomers learn about the evolution of the universe and other strange cosmic phenomena.