Dwarf Planet, type of body in the solar system that has a rounded shape like a major planet but is too small to clear other bodies from the region of space around its orbit with its own gravity. Dwarf planets orbit the Sun and may have moons and atmospheres like planets. However, they are found in regions of the solar system that contain swarms of other small bodies: the asteroid belt, the Kuiper Belt, and the Oort Cloud. Recognized dwarf planets include Pluto (formerly counted as the ninth planet), Eris, and Ceres (formerly considered the largest asteroid). See also Planetary Science.