Pluto no longer a planet

http://www.physicspost.com/science-article-215.html

This article is pretty interesting, it speaks about how Pluto was revoked from our solar system as a planet. Each celestial body has to fit a certain criteria before being called a planet. It has to be in orbit around the sun, have a sufficient mass, and has to clear the neighborhood. This consideration of planet characteristics is not agreed upon by all astronomers.