A mysterious fast radio burst (FRB) that hit Earth late last month has been detected. The part that's puzzling scientists is not the radio burst itself, but the fact that its frequency is nearly 200 megahertz lower than any other radio burst ever detected. "Additional FRBs have been found since FRB 180725A and some have flux at frequencies as low as 400 MHz," Boyle wrote. While Astronomer's Telegram lets astronomers submit genuine claims, FRB 180725A has not yet been independently verified, leaving the possibility that it could be explained. USA Today reports that in 1998 a radio signal found in space was later found to have originated from a microwave.