If you know how to listen, moons are not as quiet as you think. The principal investigator for NASA's Juno mission, Scott Bolton, has produced an audio recording of magnetic field activity around Jupiter's moon Ganymede as the Juno spacecraft flew past on June 7th, 2021. The 50-second clip shows a change in activity as the probe entered a different part of the magnetosphere.
The audio came from the electric and magnetic frequencies. Jupiter's magnetosphere dominates that of its moons and is present in the recording, but the only moon in the Solar System to have a magnetic field is Ganymede. This isn't something you could do in the future.
The mission team revealed the most detailed map yet of Jupiter's magnetic field with the help of the soundtrack. The data showed how long it would take for the Great Red Spot and the Great Blue Spot to move around the planet. The findings showed that the Great Blue Spot is being ripped apart by jetstreams and that polar cyclones are similar to ocean waves.
You wouldn't be able to hear these sounds if you went to Ganymede. They remind you that even dead worlds are often filled with activity you can detect using the right instruments. It's a question of how easy it is to notice that activity.
