How are the Galilean moons stable?

[MAFman]

It seems to me, based on intuition alone, that a 1:2:4 resonance like what's found in the Jovian system would be unstable because you have the three moons tugging on each other at the same times in each orbit. How is this stable, if it is?

[Pixophir]

This is an excellent question ! Orbital resonance is the cause of both stability and instability. On top of that, there are instabilities and perturbations from inside and outside. Even if seen as an "adiabatic" system (without external interaction), will it fly apart sooner or later ? How long can this be stable ?

I am not sure if there is a clear answer at all or if there is a solution to the problem.

Here's a text I found via stackexchange. Have no time right no to digest it all. It doesn't answer the question but gives on overview of the mechanics involved:

https://www.lpl.arizona.edu/~renu/malhotra_preprints/rio97.pdf

 

Edited August 18, 2022 by Pixophir

[NFUN]

keep in mind that they're never in a line on the same side of jupiter