Quaoar
It is the newest ‘planet’ of the solar system. It is one-tenth of the size of Earth. Its orbit around the Sun takes 288 years. Its of the size of all asteroids in the solar system put together. Called Quaoar (Kwah-o-wahr), this KBO dwells in the Kuiper belt outside Pluto. This belt is the remains of the bits and pieces left after the planet formation. It is a breeding ground for comets encircling the sun. You can read more about the newest addition to the solar system here, here & here.