Pallas, minor-planet designation2 Pallas, is the second asteroid to have been discovered (after Ceres), and it is one of the largest asteroids in the Solar System. With an estimated 7% of the mass of the asteroid belt, it is the third-most-massive asteroid, being 10–30% less massive than Vesta. It is in diameter, somewhat smaller than Vesta. It is likely a remnant protoplanet.