Now, according to the IAU, all solar system bodies similar to Pluto will be called “plutoids.”

Thus, Pluto will be the benchmark by which all bodies will be judged: either “plutoid” or not “plutoid.”

The International Astronomical Union (IAU) is an international astronomical organization—the largest such body on Earth—comprising of nearly 10,000 professional astronomers from around the world.

Founded in 1919, the IAU serves as the international authority for assigning designations to celestial bodies and the surface features on them.

The website of the International Astronomical Union states that its mission is “… to promote and safeguard the science of astronomy in all its aspects through international cooperation." [IAU: “About the IAU”]

In other words, Pluto is now the “benchmark” by which all plutoids will be named. This announcement is probably a good idea since a whole lot of controversy erupted after Pluto was kicked out of the “planet” category in 2006.

Many astronomers were very angry at the demotion of Pluto.

Please read these articles concerning the controversy (there are plenty more out there):

Space.com: “Pluto Demoted: No Longer a Planet in Highly Controversial Definition”

Johns Hopkins University: “Pluto's demotion sparks new controversy, praise”

When Pluto was demoted to “dwarf planet,” the IAU was preparing to create such a new category. Thus, the Committee on Small Body Nomenclature proposed the name “plutoid.” It was then accepted by the Board of Division II and by the IAU Working Group for Planetary System Nonenclature.

The General Assembly of the IAU introduced the category of “plutoid,” or a transneptunion dwarf planet similar to Pluto. And, two years later, in 2008, the category “plutoid” was approved by the IAU Executive Committee at its Oslo, Norway meeting.

Whom is in this exclusive group of plutoids? Please read on.