Pluto is called as Planet X before when it is found in 1930.
Back to 2010
Few years before 2010, it had a news about Pluto was found not clearing the neighborhood around its orbit by IAU ( International Astronomical Union ). They considered that it is not planet which should not be the member of solar system.
One spacecraft had set out from 2007 and it would reach the Pluto in 2015. They considered this is the last chance to approve the Pluto is belong to a member or not in our solar system.
Now is 2017
We all have known that the Pluto should be fate out in solar system by IAU confirmed. Anyway, I still support to keep Pluto alive as the ninth planet in solar system.