Mysterious "chirping" waves have been detected 160,000 km from Earth. What are they and how do they sound? Listen to the audio for more details.

Astronomers have discovered something unusual in Earth's magnetosphere, approximately 160,000 km from our planet. They detected brief bursts of energy, known as chorus waves, in a region of the magnetosphere where they have never been observed before, puzzling scientists. The study has been published in the journal Nature, as reported by Smithsonian Magazine.

Chorus waves are often referred to as "chirping" waves, although no sound can be heard in space. They are called chorus waves because they resemble birdsong when converted into audio signals.

Until now, astronomers had only found chorus waves near Earth at a maximum distance of 50,000 km. However, using the Magnetospheric Multiscale spacecraft, researchers discovered chorus waves at a distance of 160,000 km, challenging the existing theory on how these phenomena occur.

Previously, scientists believed that chorus waves could only be generated near a dipole magnetic field, which features northern and southern magnetic poles, like Earth's. These waves have also been detected around other planets with magnetic fields, such as Saturn and Jupiter.

Chorus waves are thought to be caused by plasma instability, which is outside of its equilibrium state. This disturbance can lead to chaotic electron behavior, spiraling along Earth's magnetic field lines and producing radiation that interacts with other electrons. The resulting chorus waves travel along the curved magnetic field from pole to pole, creating their "chirping" sound as they move. Below, you can listen to the sounds of the detected chorus waves.

The recently discovered chorus waves are located in a highly elongated and distant part of Earth's magnetosphere, indicating a different possible cause for their origin. Instead, they may be triggered by frequency changes as they move within the magnetic field.

Scientists do not completely dismiss the original theory, but the new study suggests the need for further observations of chorus waves. Researchers now aim to discover more such phenomena in similarly remote regions of space.

The findings of this research are significant for future space studies, as chorus waves have the potential to produce high-energy "killer electrons" that can disrupt satellite communications. Understanding these powerful particles may also help protect astronauts during crewed missions.