Originally Posted by Pawnmower
Depends on what you call rogue (is it all a part of the grand plan?) but the galaxy is a huge place...SO I would say 100%....(new stars , cooling down have planets form and the orbits arent stable yet)...(In addition singularities / super novae can occur and begin to cause unstable orbits and drawing solar systems near to them inward etc...)
If you define 'rogue' as 'non stable orbit' then the odds of your question are 100%....
Although I have a feeling you meant solar system (instead of galaxy)....in which case that drops the odds to 0%, since the orbits of the planets and moons have all been relatively stable for a million years or more.
How do you know they've been "stable" for millions of years or more? There are objects in the galaxy that we've never seen ... let alone things that, if we did see, we wouldn't understand.
On top of that, there are massive explosions taking place in our galaxy all the time. Enormous blasts of energy from dying stars or super novas or big paper bags or galactic bubble wrap. Any one of those events could break a large object out of orbit and send it hurtling willy-nilly through space and, assuming it's big enough, it could pick up other objects into its gravitational field as it travels.
I, therefore, urge you to revise and amend your prior remarks.