For the first time fifty years ago, scientists have seen strange sounds on the edge of the stratosphere and the universe. The origin of the noise was not clear to the researchers. However, the infrasound signals amaze with striking intensity and complexity. Researchers are preparing for new experiments.

Strange sounds were gleaned by the device developed by Daniel Bowman, a postgraduate student at North Carolina University, in one of NASA's projects. During the experiment, special microphones were picked up in the upper atmosphere of the helium balloon. The balloon rose up to the height of 37.500 meters. This is much higher than the airplane level, but it's also below the boundary between the stratosphere top layer and the universe.

As a result, the microphones caught whistling and noise at frequencies lower than 20 Hz. For the human ear the signals are indistinguishable, and the record from a special microphone has to be accelerated to hear mysterious sounds.

“It reminds a little The X-Files Bowman said, adding that he was shocked by signal intensity and versatility.

The source of these strange sounds remains a mystery for scientists. There are many assumptions and assumptions. For example, some believe it is the echo of ocean waves, gravitational waves, air turbulence, and even the turbulence of the helium balloon cable itself, which brought the recording device into the air. Natural phenomena such as storms and earthquakes can also produce such sounds.

Despite the fact that the exact source of the low frequency signal can not yet be determined, the experiment has already been recognized as a great success. For the first time in 50, the soundtrack was made in the stratosphere, says Bowman. Scientists are already preparing for a new experiment to be held this summer.