Pluto (Planet)

Description
Pluto ,  formally designated   134340 Pluto, is a large  trans-Neptunian object  in the  Kuiper belt. It is the second-most-massive  dwarf planet  known in the Solar System  (after  Eris ) and the tenth-most-massive body observed directly orbiting the  Sun. Like other Kuiper belt objects, Pluto is composed primarily of rock and ice [14]  and is relatively small, approximately one-sixth the mass of the  Earth 's  Moon  and one-third its volume. It has an  eccentric and highly inclined orbit that takes it from 30 to 49  AU  (4.4–7.4 billion km) from the Sun. This causes Pluto to periodically come closer to the Sun than  Neptune. As of 2011, it is 32.1 AU from the Sun.

Also, still definitely a planet.