What Makes Up the Electromagnetic Spectrum?

For 17 years, scientists have been trying to uncover the source of mysterious radio signals being picked up by the telescope at the Parkes Observatory in Australia.

Theories about the signals have included evaporating black holes and alien communication.

However, the scientists now believe they have found the answer – the microwave in the observatory’s staff kitchen!

The scientists knew the strange signals, known as perytons, originated somewhere close to Earth. However, until a new interference receiver was installed at the beginning of this year, they didn’t realise just how close!

The new receiver began picking up strong signals at 2.4 GHz – the signature of a microwave oven. Testing of the microwave in the staff kitchen did not show up with perytons until they opened the oven door before it had finished heating.Within a fraction of a second, the receiver picked up microwave activity and the source of the perytons was revealed!

Subsequent tests showed that a peryton can be generated when a microwave door is opened prematurely. Further detective work revealed that over the years the signals had tended to be transmitted lunchtime – and not in the evenings or over weekends.

While the mystery of perytons has been solved, scientists at the Parkes Observatory are still trying to work out the source of many other fast radio bursts that appear to come from space. While alien life has not been ruled out, the scientists say all kitchen appliances have!

Watch What Makes Up the Electromagnetic Spectrum? to learn more about radio waves.