Singing comet

Rosetta has five tools for studying plasma near the comet, the Rosetta Plasma Consortium (RPC) is engaged in this.

RPCs observe the activity of the comet itself, study the structures and dynamics of its plasma “atmosphere”, how its tail interacts with the solar wind and measure the physical characteristics of its core and surface.

When scientists began to study changes in the magnetic field, it was discovered that the comet, in a sense, "sings" at frequencies of about 40-50 millihertz. In order to better understand this strange "song", scientists increased the frequency of the recorded vibrations 10,000 times and presented them in the form of sound.

One of the explanations for these fluctuations today is the ionization of neutral particles from comet emissions (jets).
As soon as they enter the open space, high-energy particles from the interplanetary space collide with them. Since These ionized particles are electrically charged, the plasma consisting of them interacts with the comet's magnetic field, giving rise to these very oscillations.
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This “music” was first detected by a magnetometer (RPC-Mag) in August, when Rosette was 100 kilometers from a comet.

You can listen here: https://soundcloud.com/esaops/a-singing-comet