Solar System

This site tells the story of the history of the universe. Click Earlier and Later to follow the story.
Note: Many facts have been simplified to make them easier to understand.
Our new free weekly podcast Time Crystal tells this story as sci-fi fantasy

Recent discoveries of planetary systems outside our own are challenging current ideas on how the Sun and its nine planets, the solar system, originally formed. The story which follows, therefore, may soon be changed in the light of new discoveries.

Two large planets, Jupiter and Saturn, were the first to form. They are mostly gas. These massive planets probably had a great influence on how the rest of the solar system evolved. For some reason they were in almost perfect circular orbits. This is unusual. In the few other planetary systems studied so far, most of the giant planets are in oval (elliptical) orbits.

Later four small rocky planets formed near the Sun: Mercury, Venus, Earth and Mars. As we shall see, life later evolved on one of these (Earth). These planets too had almost circular orbits. If they had oval orbits, life could not have evolved.

Another planet started to form but broke up into pieces because of the gravity of Jupiter. It formed a ring of small rocks where the planet should have been. We call them the asteroids.
Beyond Saturn there are two gassy planets, Uranus and Neptune and a little icy planet Pluto. Far out beyond Pluto there are many icy objects like the snowballs which formed the planets. They are the comets, and sometimes one of them wanders in near the Sun.