Another difference between Earth’s magnetic instrument and the ones we’re more used to is how it changes in time. Play a note on a musical instrument a few minutes, hours or even days apart and you wouldn’t expect much of a difference in the sound produced. That’s because not much has changed. Sure, eventually the instrument may need retuning by say tightening up the strings, but that’s usually after quite some time.
The magnetosphere, on the other hand, is almost always changing – it grows and shrinks in direct response to the ever fluctuating solar wind. One would imagine this should change the notes of the magnetosphere, given how a musical instrument works.
This is a topic I’ve been working on recently. The problem is that you can’t just listen to how the notes change because it’s often not possible to be sure what triggered the waves detected or what sort of resonance built up, simply because we don’t have satellites placed at all points throughout this “instrument” listening to these sounds.
One potential way around this is to calculate how all the different types of notes should change using computer models of the magnetosphere under the different observed conditions. This approach has suggested a considerable amount of variability in these notes, some 35-105%. This is comparable to between five semitones and an entire octave. Thankfully, these models have also has revealed at least some of the controlling factors such as the density of the solar wind. Of course, these are only calculations and need to be tested against reality to be sure, so there’s still more work to do.