Gas giant close encounters and habitable moons

[Junghalli]

I've been doing some research on habitable moons of gas giants (this is a follow up to the earlier questions for my uni), and I have a question.

I understand that a lot of the gas giants that orbit within the life zone are eccentric gas giants, and the main theory on how these come to be is that you have multiple gas giants that form on the same system and they have a close encounter that results in one of them being ejected from the system and the other getting put into an elliptical orbit.

Now, what would happen to the moons of the two gas giants in such a collision? Would they all be scattered? Or would the moon systems survive? What would happen to the moons orbiting the two planets during such an event?

Also, would a planet that was on a rotation-revolution resonance like Mercury that didn't have a large moon be subject to the polar axis tilt wandering and becoming periodically extreme like Mars's does, or would this not be a problem for such a world? I know Mercury has practically no axis tilt: only .01 degrees.

Thanks.

[CaptainChewbacca]

I've been doing some research on habitable moons of gas giants (this is a follow up to the earlier questions for my uni), and I have a question.

I understand that a lot of the gas giants that orbit within the life zone are eccentric gas giants, and the main theory on how these come to be is that you have multiple gas giants that form on the same system and they have a close encounter that results in one of them being ejected from the system and the other getting put into an elliptical orbit.

Sometimes you just have inward migration of gas giants without ejection.

Now, what would happen to the moons of the two gas giants in such a collision? Would they all be scattered? Or would the moon systems survive? What would happen to the moons orbiting the two planets during such an event?

Anything could happen, really. The moons would be flung apart by gravity through the solar system. Imagine if suddenly 5 earth-sized planets peeled off from Jupiter and Saturn and started migrating; they could end up anywhere in the solar system, in all kinds of unusual orbits.

Also, would a planet that was on a rotation-revolution resonance like Mercury that didn't have a large moon be subject to the polar axis tilt wandering and becoming periodically extreme like Mars's does, or would this not be a problem for such a world? I know Mercury has practically no axis tilt: only .01 degrees.

Thanks.

Anything close enough to a star to be tidally locked to the same extent as Mercury wouldn't have much wobble, because the star would stabilize it.