A joint research team detects chirping chorus from unexpected part of outer space. (Photo provided yo China News Service)

A joint research team composed of Chinese, U.S. and Swedish scientists have detected cosmic waves that sound like birds chirping in an unexpected place.

These waves, detected about 160,000 kilometers from Earth, are in fact intense electromagnetic bursts. When they are converted to audio signals, they resemble chirping birds.

The same chorus was once detected in near-Earth space before. The detection of chorus waves in deep space this time indicates that it may be quite common in the universe, and may contribute to understanding the formation of electromagnetic bursts.

According to the research team, electromagnetic bursts play a crucial role in the formation of the Earth's radiation belts, pulsating auroras, and the precipitation of particles into its atmosphere. Traditional views hold that chorus waves are formed in the magnetic field of a dipole of near-Earth space, where the magnetic field is similar to a large bar magnet.

The newly-found chorus waves were detected in a region where Earth's magnetic field is stretched out, which scientists didn’t expect. They lasted about 0.1 second with a frequency of nearly 100 hertz per second, which are similar to the waves detected in near-Earth space. That raises fresh questions about how these chirping waves form.