A dwarf planet is a planetoid.[1]


"Dwarf planet" is a misnomer used by the IAU to educate the citizen sector that Pluto is separate from the major planets. It falls under the umbrella term minor planet (historically asteroids), but is otherwise more distinctly a planetoid. After the discovery of Eris, a Kupier belt object (KBO), the reclassification of planets became a matter of importance to the International Astronomical Union (IAU). The potential discovery of more objects, in the Kuiper system, led to fears of classifying minor objects as planets. So a need to redefine a planet ensued.[2] The IAU chose to implement "dwarf" in planetary terminology, the same way they do in star classifications, as with dwarf stars and main-sequence stars (which there is also terminology confusion in stellar classification due to what a dwarf is and isn't). Subsequently, for the publics' re-education, "dwarf" was applied to minor objects, whereby Pluto, a Kuiper Belt object, was reclassified as a "dwarf planet".


The planet in "dwarf planet" and "minor planet" is a literary transitional term, to re-educate the citizen sector that there is a distinction between what is a main planet, and what isn't, in light of Pluto-having always been considered a planet prior to its re-classification by the IAU. The IAU does not, however, view any dwarf or minor object (asteroid belt and kuiper belt objects) as a planet—So the expressions "dwarf" and "minor planets" are misnomers. Because of the confusion, public reception, and hot-debates, the IAU had thus drafted an exhausted resolution paper to define what a planet is versus what the newly labelled "dwarf planet" is supposed to mean.[3]

Defining PlutoEdit

"Minor planet" was a term originally applied to Ceres in the Asteroid belt. The newly used term "dwarf planet" is applied to NTOs (Trans-Neptunian objects), which are basically planetoids beyond Neptune. Since the IAU do not view these objects as planets, it is more than likely that among themselves, they do not use "minor planet" nor "dwarf planet" when referring to Ceres, Pluto or any distinguished objects in either the Asteroid or Kuiper Belt. Distinct minor bodies whose mass supports its self-gravity are planetoids. Beyond Neptune, they are often referred to as TNOs (Trans-Neptunian objects). Reclassifying objects in the asteroid belt, especially for dwarf status, seems of less importance to the IAU, than the real issues that lie at the edge of the heliosphere.


  2. Brown, Michael E. "What makes a planet?". California Institute of Technology, Department of Geological Sciences. Retrieved January 26, 2008.