We learned about asteroids, meteors and meteorites.
We crashed different sized meteorites (balls) onto Earth (a biscuit tin with sand and a light layer of chocolate powder).
They made different sized craters (the larger the ball the larger the crater). We found that the difference in size of the meteorite affected the size of the crater and also the depth of the crater.
All this talk of meteorites and craters led us to talk about dinosaurs. We know that dinosaurs became extinct after a large asteroid hit the earth. Some of the dinosaurs may have been hit, others may have been killed by a pyroclastic flow, or probably from lack of food caused by an Ice Age (because lots of dust from the impact would have blocked out the sun's rays causing the whole earth to become very cold). This means that the plants would have all died, then there would have been no food for the dinosaurs who were herbivores. They would have died too, and then there would have been no food for the dinosaurs that were carnivores. It's a sad tale of the end of the dinosaurs!