A cold and sterile chunk of rock orbiting the sun in the vicinity of Neptune and Pluto has been officially named Makemake, after a Polynesian god. The International Astronomical Union (IAU) has also designated Makemake the solar system‘s fourth dwarf planet and third “plutoid,” as researchers’ new aptitude for locating small orbital bodies has required a new and controversial system of classification.
Astronomers discovered Makemake (pronounced MAH-keh MAH-keh)… in 2005 and believe its surface is covered by a layer of frozen methane. It is bright enough to be seen by a high-end amateur telescope [SPACE.com]. Researchers say it’s about two-thirds the size of Pluto.
Makemake will join Pluto, Eris, and Ceres on the growing list of dwarf planets. Its discovery along with that of Eris and similar specimens precipitated the IAU’s decision to create a separate category for round objects in the solar system that have not swept clear their regions of competing debris, which led to Pluto’s demotion from planet to dwarf [Scientific American]. Almost two years after the dwarf category was created, the IAU created the plutoid sub-category, defining it as any dwarf planet orbiting beyond Neptune; so far, the distinction excludes only Ceres from the plutoid club.
Lead astronomer Mike Brown had the honor of suggesting the official name for Makemake, which had previously been known as 2005 FY9 or “Easterbunny,” since it was found around Easter. The only stipulation is that the name must have a mythological origin. Brown says the dwarf planet had no physical characteristics that easily connected it with fabled names. But discovery of Makemake, Eris and a potential fourth plutoid… coincided with Brown’s wife being pregnant, he recalls. So Brown settled on the Polynesian word Makemake, which is the name for the god of fertility and also the name of the creator of humanity in the mythology of the South Pacific Island of Rapa Nui, or Easter Island [Science News].
Image: International Astronomical Union
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