ANITA was placed in Antarctica because there is little chance of interference from other signals. To capture the emission signals, the balloon-borne radio detector is sent to fly over stretches of ice, capturing what are called ice showers. Credit: Stephanie Wissel / Penn State

Researchers from the Antarctic Impulsive Transient Antenna (ANITA) were baffled to find the signals coming from the ground at seemingly impossible angles. The study used a range of instruments mounted on air balloons flown above the ice-packed continent Publishing their findings in Physical Review Letters,