Microwave Oven Baffled Astronomers for Decades

Astronomers at the Parkes Observatory in New South Wales, Australia, have been noticing strange signals coming through the radio telescope since 1998. These signals were designated as perytons, and were observed maybe twice a year. No one knew where they were coming from, but lightning was proposed as the cause. Of course, we’d all prefer it to be aliens. A new receiver installed this year picked those signals up even stronger at 2.4GHz, which led the scientists to suspect the facility’s microwave oven.

Immediate testing of the oven failed to detect any perytons -- until they opened the microwave door a few seconds before it had finished cooking. Johnston told The Guardian: "If you set it to heat and pull it open to have a look, it generates interference."
Although the telescope, known locally as "The Dish", is operated largely remotely, a few operational staff who maintain the facility would use the microwave oven to heat their lunch in the daytimes. Moreover, the interference would only occur when the telescope was pointed in the oven's direction, making the cause even harder to pinpoint. The findings have been published in the notices of the Royal Astronomical Society.

So much for aliens trying to contact us. But it’s nice that the 17-year mystery has been solved.