The third, the disk instability method, may account for the creation of giant planets. Approximately 4.6 billion years ago, the solar system was a cloud of dust and gas known as a solar nebula. ... In this way, asteroids, comets, planets and moons were created.
Solar System Formation. Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust.
