2002 MS does not have any known moons orbiting it, thus an accurate mass estimate cannot be made. Based on its size, Brown lists it as nearly certain to be a dwarf planet, however, its low albedo may imply the opposite: dark, mid-sized bodies such as this, less than about 1000 km in diameter and with albedos less than about 0.2, have likely never collapsed into solid bodies, much less differentiated or relaxed into hydrostatic equilibrium, and thus are unlikely to be dwarf planets.