Formation and evolution of the Solar System have been forged from the remnants in less violent collisions. Moons around some asteroids currently can only be explained as consolidations of material flung away from the parent object without enough energy to entirely escape its gravity. Moons have come to exist around most planets and many other Solar System bodies. These natural satellites originated by one of three possible mechanisms: Jupiter and Saturn have several large moons, such as Io, Europa, Ganymede and Titan, which may have originated from discs around each giant planet in much the same way that the planets formed from the disc around the Sun.
IAU definition of planet planets. Mike Brown, the discoverer of Sedna and Eris, has said that at least 53 known bodies in the Solar System probably fit the definition, and that a complete survey would probably reveal more than 200. The definition would have considered a pair of objects to be a double planet system if each component independently satisfied the planetary criteria and the common center of gravity of the system (known as the "barycenter") was located outside of both bodies. Pluto and Charon would have been the only known double planet in the Solar System. Other planetary satellites (like Earth and its