| − | The '''nebula hypothesis''' is a model of the formation of the solar system. It theorizes that a solar system begins as a rotating cloud of gas and dust that contracts to create a flat disk with a star at its center. Planets grow from the particles surrounding the star, creating a solar system. | + | The '''nebula hypothesis''' is a model of the formation of a solar system. It theorizes that a solar system begins as a rotating cloud of gas and dust that contracts to create a flat disk with a star at its center. Planets grow from the particles surrounding the star, creating a solar system. |