My understanding is the burgeoning gas giant eventually captures either an asteroid or remnant rocky debris which then grows through pebble accretion, but the gas giant would still be initially formed from mostly gases.
The (one) paper I read on this (while ignoring most of the confusing math bits) put the moons being captured when Jupiter was roughly 40% of its current mass.
Silliest thing I have ever heard? How would that even come about?
My understanding is the burgeoning gas giant eventually captures either an asteroid or remnant rocky debris which then grows through pebble accretion, but the gas giant would still be initially formed from mostly gases.
The (one) paper I read on this (while ignoring most of the confusing math bits) put the moons being captured when Jupiter was roughly 40% of its current mass.