In our outer solar system Pluto is a small planet and discovered in the year 1930. Pluto has a highly eccentric orbit that is greatly inclined in respect to the other planets and takes it within the orbit of Neptune .Charon is the moon of Pluto. Pluto's astronomical figure is a combination of the name's first two letters, "P-L", which are also Percival Lowell's initials, even though some prefer a different symbol resembling that of Neptune but with a circle in the top center instead of the middle spoke.

Owing to its size and unusual orbit, there has been dispute concerning whether Pluto should be classified as a major planet or as a minor planet, and there is growing momentum for recognizing "dual status" (in other words, there are good arguments for both).