Link sent in by William with the comment, here we go again. Our theories are wrong and need to be updated with the new data. Who is to say it never belonged there?
Go https://www.msn.com/en-us/science/astronomy/saturn-captures-this-moon-4-billion-years-ago-and-it-never-belonged-there/vi-AA1WIS15 …. the link is to a video. Make sure your audio is working.
Apparently, Phoebe is not just another moon – it is a cosmic trespasser. It orbits Saturn at high speed and moves in the opposite direction to that of the planet’s rotation. Phoebe, we are informed, violates the basic rules of how moons are supposed to form. Who dreamt up those rules and are they valid?