For the first time in a span of fifty years, a peculiar ‘infrasounds’ was captured from the fringes of space.
The sounds were recorded on-board a helium-filled-balloon student experiment, by means of infrared ultra-sensitive microphones.
Inexplicable hisses, whistles and whizz recordings were featured and recorded at 22 miles (36km) above the Earth’s exterior.
Different theories were formulated as to the source of the sounds ranging from wind in the balloon’s path, to oceanic waves, gravitational waves and clear air turbulence.
Others deduce the noises may have come from the balloon cable movements.
Daniel Bowman, a University of North Carolina, Chapel Hill, student first captured the sounds.
NASA is planning a project later this year, to send another payload to record more of these strange noises, reports LiveScience.
Bowman was quoted as saying, “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.”
Infrared microphones strapped to a balloon filled with helium and was released by Bowman above Arizona and New Mexico on August as part of the High-Altitude Student Platform study.
Floating at 725 km from the Earth’s surface, the balloon reached a more that 37,500 meters more in terms of height.
Infrasonic sounds or low-frequency sounds are sounds which are produced by waves that are at frequencies below 20 hertz (HZ) or cycles per second, the normal level of human hearing. As frequency decreases, hearing becomes less sensitive.
Sounds at these low frequencies are imperceptible by the human ear.
A crucial distinctive characteristic of infrasonic sound is that can travel long distance.