Lunar and Planetary Institute
Lunar and Planetary Institute


IAU Approves Name of Fourth Dwarf Planet

August 19 , 2008
Source: International Astronomical Union

Artist's illustration of the dwarf planet Makemake. Credit: IAUThe International Astronomical Union (IAU) has given the name Makemake to the newest member of the family of dwarf planets — the object formerly known as 2005 FY9 — after the Polynesian creator of humanity and the god of fertility.

Members of the IAU’s Committee on Small Body Nomenclature (CSBN) and the IAU Working Group for Planetary System Nomenclature (WGPSN) have decided to name the newest member of the plutoid family Makemake, and have classified it as the fourth dwarf planet in our solar system and the third plutoid.

Makemake (pronounced MAH-keh MAH-keh) is one of the largest objects known in the outer solar system and is just slightly smaller and dimmer than Pluto, its fellow plutoid. The dwarf planet is reddish in color and astronomers believe the surface is covered by a layer of frozen methane.

Like other plutoids, Makemake is located in a region beyond Neptune that is populated with small solar system bodies (often referred to as the transneptunian region). The object was discovered in 2005 by a team from the California Institute of Technology led by Mike Brown and was previously known as 2005 FY9 (unofficially “Easterbunny”). It has the IAU Minor Planet Center designation (136472). Once the orbit of a small solar system body or candidate dwarf planet is well determined, its provisional designation is superseded by its permanent numerical designation.

The discoverer of a solar system object has the privilege of suggesting a name to the IAU, which judges its suitability. As Brown explains, “We consider the naming of objects in the solar system very carefully. Makemake’s surface is covered with large amounts of almost pure methane ice, which is scientifically fascinating, but really not easily relatable to terrestrial mythology. Suddenly, it dawned on me:  the island of Rapa Nui. Why hadn’t I thought of this before? I wasn’t familiar with the mythology of the island so I had to look it up, and I found Makemake, the chief god, the creator of humanity, and the god of fertility. I am partial to fertility gods; Eris, Makemake, and 2003 EL61 were all discovered as my wife was 3–6 months pregnant with our daughter. I have the distinct memory of feeling this fertile abundance pouring out of the entire universe. Makemake was part of that.” The WGPSN and CSBN accepted the name Makemake during discussions conducted per e-mail.

Makemake holds an important place in the solar system because it, along with Eris and 2003 EL61, was one of the objects whose discovery prompted the IAU to reconsider the definition of a planet and to create the new group of dwarf planets. Visually, it is the second brightest transneptunian object, following Pluto, and is bright enough to be seen through a high-end amateur telescope (a peak magnitude of roughly 16.5).

The other three dwarf planets are Ceres, Pluto, and Eris. However, Ceres is not a member of the distinctive plutoid group because its orbit is smaller than Neptune’s (Ceres is located in the asteroid belt between Mars and Jupiter).

The word Makemake is Polynesian in origin and is the name of the creator of humanity and the god of fertility in the mythology of the South Pacific island of Rapa Nui (Easter Island). He was the chief god of the Tangata manu bird-man cult and was worshiped in the form of sea birds, which were his incarnation. His material symbol was a man with a bird’s head.

For more information, visit

Pluto and the Developing Landscape of Our Solar System

Mike Brown’s Website at Caltech

International Astronomical Union



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