Extraterrestrial liquid water not. Similar indirect evidence, however, supports the existence of liquids below the surface of several moons and dwarf planets elsewhere in the Solar System. Some are speculated to be large extraterrestrial "oceans". Liquid water is thought to be common in other planetary systems, despite the lack of conclusive evidence, and there is a growing list of extrasolar candidates for liquid water. As of December 2015, the confirmed liquid water in the Solar System outside Earth is 25-50 times the volume of Earth's water (1.3 billion cubic kilometers). Water on Mars exists today almost exclusively as ice, with a small amount
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.