Radio pulses that look like they came from deep space could actually have earthly origins.

A team led by Pascal Saint-Hilaire at the University of California, Berkeley, detected five short but intense radio bursts at the Bleien Radio Observatory in Switzerland. This is only the second location at which such pulses have been detected, and their origins are still unclear. Characteristics of the radio waves suggest that they were stretched after passing through vast amounts of plasma — usually indicating an origin outside of the Milky Way, such as exploding stars in other galaxies.

However, the pulses were detected only when the antenna was in a mode susceptible to ground interference, and all but one pulse occurred in the late morning. This suggests that the signals could actually be coming from sources on Earth.

Astrophys. J. 795, 19 (2014)