3.7 A very Nice model
As Bill Bottke says in this video, samples brought back from the Apollo mission went a long way to develop our current understanding of the evolution of the Solar System. Our models are constantly being reviewed and refined with new scientific data. Notice in the Nice model how Jupiter migrated inwards, Saturn migrated outwards, and the orbits of Neptune and Uranus were swapped over from their original locations. This re-structuring after the formation of planets could have been a trigger for the formation of many of the moons in the Solar System, and could also explain the heavy bombardment suffered by the Moon about four billion years ago.
The video shows how gravity can influence the growth and the orbits of planets. Next you will look at how mutual gravitation acts to produce tides, and how this can affect the orbit, rotation and internal heating of a moon.