 Ovenden suggested that the planet be named "Krypton" after the destroyed native world of Superman, as well as believing it to have been a gas giant roughly eighty-five to ninety Earth masses in mass and nearly the size of Saturn.Today, the Phaeton hypothesis has been superseded by the accretion model.Most astronomers today believe that the asteroids in the main belt are remnants of the protoplanetary disk that never formed a planet, and that in this region the amalgamation of protoplanets into a planet was prevented by the disruptive gravitational perturbations of Jupiter during the formative period of the Solar System.