A planetoid, also known as a minor planet or dwarf planet, is an astronomical object that orbits the sun and is not considered a full-fledged planet due to its size. It is generally smaller than Mercury and Pluto, and larger than a meteoroid. Planetoids are classified as such if they have enough mass to pull themselves into a round shape, but not enough to clear their orbit of other debris. Currently, there are five identified planetoids in the solar system: Ceres, Pluto, Haumea, Makemake, and Eris.