Researchers at Parkes Observatory in Australia have released a study showing mysterious radio signals that appear to be from deep space, known as perytons, are actually impatient microwave oven users. By prematurely opening up the microwave, a powerful radio burst can escape the oven, and confuse the telescopes.

“It was quite surprising that it ended up being microwaves,” says study author Emily Petroff of Australia’s Swinburne University of Technology.

Astrophysicist Emily Petroff and her team, installed a radio interference monitor at the telescope to discover the source of perytons. After finding signals similar to microwave ovens, the team found they could make perytons on demand by opening their microwave before the timer had finished. Microwave ovens are typically shielded with a Faraday cage, or that funky metal grating over the door.  Other radio telescope observatories ban microwaves in an attempt to remove as much Earth-based interference as possible.