Topic: Eris (Dwarf Planet)
Long considered a planet, Pluto was reclassified as a 'dwarf planet' in 2006 by the International Astronomical Union. Will the discovery of a fifth moon prompt astronomers to reconsider?
Cal Tech astronomer and author Mike Brown helped to demote Pluto from planethood – and got a lot of hate mail as a result.
New calculations indicate that Pluto might be the largest object in the outer solar system. Does it now deserve to be called a planet again?
Ceres and Pluto will come into opposition with the sun, offering a rare view of these two dwarf planets.