Eerie sounds in stratosphere has people wondering about alien signals

Eerie sounds picked up in the upper atmosphere have NASA scientists baffled, and thousands of people wondering whether it could be evidence of signals coming from intelligent aliens in deep space. Whatever their origins, NASA says it plans to find out by sending up more balloons.

The mysterious whistling and hissing sounds were captured twenty-two miles (35 kilometres) up in the stratosphere by a NASA student balloon.

Daniel Bowman, a University of North Carolina at Chapel Hill doctoral student who detected the weird sounds, described the enigma like something out of an X-Files series.

Signal from aliens

Could these mysterious sounds come from intelligent aliens, or is there a more down-to-Earth explanation?

Mr. Bowman captured the sounds with infrared microphones he designed and built himself, then attached to the balloon.

The infrasounds – sounds appearing at frequencies below 20 hertz – are too low-pitched to be heard by human ears. The only way we can hear the recording is to speed it up.


Infrasonic sound

Low frequency sound, or infrasonic sound, can travel very long distances. Natural occurrences such as earthquakes, storms and sea waves crashing can cause them.

In this case, however, scientists are completely at a loss as to where they came from.

Scientists offering suggestions for possible causes

Although there is currently no clear evidence regarding the strange sounds’ origin, scientists have offered these possible suggestions to LiveScience:

– clear air turbulence,

– gravity waves,

– the balloon cable flapping or vibrating,

– wind turbulence,

– ocean waves, and

– a wind farm below the balloon’s flight path.

Bowman and balloonDaniel Bowman and a NASA student balloon. (Photo:

In an interview with LiveScience, Mr. Bowman said:

“I was surprised by the sheer complexity of the signal. I expected to see a few little stripes.”

Mr. Bowman, who has been designing, building and launching high-altitude balloons since he was a teenager, hopes that his research will encourage people to become more interested in atmospheric infrasound.

Mr. Bowman said:

“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.”

NASA has recently become more interested in searching for alien life in space. It said in April it was stepping up its quest to find extraterrestrial life outside our solar system by bringing together eminent scientists from various fields.

Video – Recording of the eerie sounds

So that we can hear them, the recording has been sped up.