Since Pluto was demoted years ago to a non-planet, we have been stuck with 8 planets.  But over the last year there has been a lot of discussion about there being  a planet 9.  From 60 minutes.  The question is will we see it in out lifetime?

http://www.cbsnews.com/news/60-minutes-cal-tech-astronomer-hunts-for-planet-nine/