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.
Mongo (fictional planet) peoples of Mongo have evolved into different forms, such as the winged Hawkmen, the tailed Lion Men, and the underwater dwelling Coralians. Mongo is about half the diameter of Earth but is considerably denser, so its gravity is only slightly weaker than the Earth's, though it still allows Flash Gordon to put his gymnastics skills to good use. Mongo has a variety of climates, and is inhabited by enormous, dinosaur-like monsters. In Alex Raymond's comic strip and the Flash Gordon movie serials, Mongo was shown as a rogue planet that had drifted into Earth's solar system. Later versions of the