Now, with a volunteer or two to play the part of a nearby star about to go supernova , we'll provide the energy to transform this nebula into a solar system. A supernova is a large star at the end of its main sequence that has exhausted its hydrogen fuel, loses its self-gravitation, and leterally lets go of itself. It releases an abundance of energy in a massive outside expansion, sending out shock waves and matter into the floating nebula, which now starts to stir, swirling around. It was that initial energy that set up the motion that is still visible today as the Sun spins around and the planets spin in orbit around the Sun. At this point, let's view it in slow motion, as everyone in the room is now swirling around.
Some partners pull together at center to become the protosun .
Some clump together to become planets, moons, asteroids. Some debris is scattered in the outlying regions, chunks of rock and ice, forming comets. As the protosun grew, its gravitational pull caused a great amount of material to fall from the outer regions to the inner, a time of many impacts. We can see the record of this process in the cratering on moons and planets. At some point, things inevitably become creatively chaotic, and the action must come to a stop, with everyone freezing in position, taking a moment to look at the similarity of their positions to the pictures of the early solar system.