THE JUNO PROBE HAS RECORDED THE ‘SOUND’ OF JUPITER’S MOON GANYMEDE

You might expect moons to be deafeningly quiet in comparison to their host planets, but that isn’t entirely true — at least not if you know how to listen. Scott Bolton, the principal investigator for NASA‘s Juno mission, has created an audio recording of magnetic field activity around Jupiter’s moon Ganymede as the Juno spacecraft flew past it on June 7th, 2021, as part of his ongoing research. After entering a different part of Ganymede’s magnetosphere for 50 seconds, the probe’s activity changes dramatically, possibly as it transitions from the night side to the daylight side. This is revealed in a 50-second video clip.

The audio was produced by bringing electric and magnetic frequencies into the audible range through frequency shifting. Jupiter’s magnetosphere dominates that of its moons, and it can be heard in the recording, but Ganymede is the only moon in the Solar System that has a magnetic field, and it is the only moon that has a magnetic field (likely due to its liquid iron core). This isn’t something you’ll be able to duplicate anywhere else in the near future.

In addition to the soundtrack, the mission team revealed the most detailed map of Jupiter’s magnetic field to date during a larger Juno briefing. Using the data, scientists were able to calculate how long it would take the Great Red Spot and the equatorial Great Blue Spot to circle the planet (roughly 4.5 years and 350 years respectively). The findings also revealed that east-west jetstreams are tearing apart the Great Blue Spot, and that polar cyclones behave in a similar way to ocean vortices on the surface of the Earth.

If you had the opportunity to visit Ganymede, you would not have heard these sounds. However, they serve as a reminder that even seemingly dead worlds are frequently teeming with activity that can be detected with the proper equipment. Just how easy it is to notice that activity is a matter of personal preference.