Question: will there ever be any extra planets in our solar system

Hayley Evers-King answered on 18 Mar 2013:

I don’t think so no. We’ve probably got good enough telescopes and probes to have found all the big objects in our solar system that would qualify as planets. It would be very unlikely that new ones would form, unless a really big asteroid or something came from outside the solar system and smashed up some of the current planets – maybe then new ones would form out of the remains, but at the moment there is not enough matter floating around freely to just form another planet outside of the influence of the current planets gravities.