An object similar to those two was "downgraded" to this status in 2006.
By definition, this type of object does not clear the neighborhood around its orbit. Haumea (how- MAY-uh), found in 2003, and Makemake (MAH-keh-MAH-keh), found in 2005, are two examples found in the Kuiper (KYE-per) Belt. An object similar to those two was "downgraded" to this status in 2006. For 10 points, Eris and, since 2006, Pluto are what type of celestial body that is smaller than a true planet?
By definition, this type of object does not clear the neighborhood around its orbit.
dwarf planet [accept dwarf after "planet" is read but prompt before; do not accept "planet" by itself]