Answering the question as to why the moon has so many craters, we talked about how the earth's atmosphere burns up many meteors that would otherwise hit the earth, but that the moon doesn't have such atmosphere. We talked about the light that comes from a shooting star and how it is the atmosphere rubbing against the meteor that makes the energy in the form of light. To determine why the craters on the moon differ in size, we did two experiments. The first was to see how the size of the rock would affect the size of the crater. We took a large bowl of flour and smoothed its surface by shaking the bowl gently back and forth. Then we used a spot on a nearby post to determine the height at which they would drop their rocks. In this way we eliminated a variance of speed affecting our results. As expected, the larger the rock, the larger the crater. We also noticed, however, that the craters were considerably larger than the rock that made it. Scientists estimate that the size of a crater on the moon will be about 20 times larger than the rock that created it.We then did a second experiment in which the size of the rock remained constant and the height at which we dropped the rock increased with each drop. As expected, the larger the impact (or the higher the drop) the larger the crater. With the highest drop, the stone bounced up and made a second crater. We noticed when we looked at pictures of moon craters, that the craters were almost always perfectly round. We learned that no matter the initial shape of the meteor or the angle of the impact, the resulting crater is always round. I also had them recall an experiment that Katie had led last year in which she photographed drops of water falling in a pan of water. They discovered then that as soon as the drop hits, it goes below the surface of the water, making a sort of crater, that ripples come from the center, hit the walls of the pan and bounce back and forth and that a mound of water forms in the center of the crater right after the drop is dropped.
Very large meteors have struck the moon so fast that they melt the rocks and the moon's surface turned into molten rock for a few minutes. It then solidifies before the peak has a chance to become level again. These craters then have a central peak.
Another Version of Making Craters (this time with pudding!)