The Sound of Comet 67P

Posted on February 6, 2017

Did you know the European Space Agency has successfully orbited Comet 67P for 18 months, and landed a lander to examine the comet up close.

Unfortunately instead of a smooth landing, the lander bumped and hopped and landed onto another unforeseen landing spot, without any sunlight to power-up and was lost.

However, it did manage to perform 80% of its scientific tasks before shutting down.

This comet holds a lot of mysteries, one of them is the sound it produces. The Scientist were baffled when they discovered this, and are still looking for a good explanation.

But one observation has taken the RPC scientists somewhat by surprise. The comet seems to be emitting a song in the form of oscillations in the magnetic field in the comets environment. It is being sung at 40-50 millihertz, far below human hearing, which typically picks up sound between 20 Hz and 20 kHz. To make the music audible to the human ear, the frequencies have been increased by a factor of about 10,000.

The music was heard clearly by the magnetometer experiment (RPC-Mag) for the first time in August, when Rosetta drew to within 100 km of 67P/C-G. The scientists think it must be produced in some way by the activity of the comet, as it releases neutral particles into space where they become electrically charged due to a process called ionisation. But the precise physical mechanism behind the oscillations remains a mystery.

This is exciting because it is completely new to us. We did not expect this and we are still working to understand the physics of what is happening, says Karl-Heinz.

Excerpt form ESA’s Rosetta blog.