About years ago, there was a star that was than our sun, and the life of the star ran out, resulting in a(n) This left behind a that later turned into the sun and planets.The debris left behind by the previous star formed into a which underwent differentiation by the newly-formed in the center of the cloud. This cloud is referred to as the The caused the to get pushed farther out to the edges of the disc, where the material formed into the planets. Closer to the sun are the planets, including Earth. After Earth had formed, the moon formed when Half a billion years later, the happened and resulted in a bunch of that we still see on the moon and other bodies in the solar system..