Pallas (minor-planet designation: 2 Pallas) is the second asteroid to have been discovered, after 1 Ceres. Like Ceres, it is believed to have a mineral composition similar to carbonaceous chondrite meteorites, though significantly less hydrated than Ceres. It is the third-largest asteroid in the Solar System by both volume and mass, and is a likely remnant protoplanet. It is 79% the mass of 4 Vesta and 22% the mass of Ceres, constituting an estimated 7% of the mass of the asteroid belt. Its volume is equivalent to a sphere in diameter, 90–96% the volume of Vesta.