The definition of planet set in Prague in 2006 by the International Astronomical Union (IAU) states that, in the Solar System, a planet is a celestial body which:
(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects, except satellites, orbiting the Sun shall be referred to collectively as "Small Solar System Bodies"