Earlier this month, we reported on an ongoing legal battle between iRobot and the National Radio Astronomy Observatory over the use of certain radio signals for commercial purposes (specifically, a robotic lawn mower). Well, it turns out that the NRAO had good reason to be worried.
For years, scientists working at radio telescope in southeast Australia have been recording a series of strange radio signals, called perytons, that appeared to be coming from the farthest reaches of space. Disappointingly, they were actually just microwaves.
The radio waves were picked up as "short bursts" by Australia's Parkes Observatory, and date as far back as the 1990s. National Geographic reports that it wasn't until researchers installed a real-time radio interference monitor that they realized the perytons were strangely similar to the waves emitted by microwave ovens.
Sure enough, the culprit was just a couple of microwaves in the staff kitchen and visitors center, which made sense given the signals were usually picked up around lunchtime.
Inquisitive minds may ask, why were the bursts were so short? It's because they would occur when lunchers opened the microwave door before the timer went off. Since microwaves are momentarily active when you open the door in this manner, some of that electromagnetic energy would escape and get picked up by the telescope.
National Geographic points out that other radio observatories tend to house their electromagnetic devices in Faraday cages, which prevent these signals from escaping.
As to whether the Parkes Observatory intends to place its microwaves in Faraday cages or remove them from the premises, it's unclear. What is clear, however, is that perytons are not an attempt by distant aliens to make contact with Earth.