Eerie sounds from the edge of space were recorded for the first time in 50 years aboard a NASA student balloon experiment.

Infrasound microphones captured the mysterious hisses and whistles 22 miles (36 kilometers) above the Earth’s surface last year. Daniel Bowman, a graduate student at the University of North Carolina at Chapel Hill, designed and built the equipment. The instruments eavesdropped on atmospheric infrasound, or sound waves at frequencies below 20 hertz. Infrasound is below human hearing range, but speeding up the recordings makes them audible.

Bowman, who has been building and launching his own high-altitude balloons since high school, hopes that his experiment will revive interest in atmospheric infrasound. “There haven’t been acoustic recordings in the stratosphere for 50 years. Surely, if we place instruments up there, we will find things we haven’t seen before,” he said.

Here is the recording

Fonte/Source: Live Science