Astronomers have upgraded a distant rock discovered in 2005 to the category of dwarf planet, the controversial designation created two years ago by the International Astronomical Union (IAU) to deal with planetlike bodies far out in the solar system. The IAU decided at a meeting last week that the object formerly known as 2005 FY9 (or unofficially, "easterbunny") will henceforth be known as Makemake (pronounced MAH-kee MAH-kee) for the Polynesian god of fertility and creator of humanity. That makes it the fourth dwarf planet, joining Ceres, Eris and Pluto, and the third "plutoid," or dwarf planet beyond Neptune. (Ceres resides in the asteroid belt between Mars and Jupiter.) Slightly smaller than Pluto and nearly as bright, reddish Makemake is one of the largest objects in the outer solar system. 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.

Image credit: Ann Feild (Space Telescope Science Institute)