10: War of the Worlds- How Impacts Build Planets
- Page ID
- 25251
How was the Earth formed? How did the Moon get here? Are all planets formed in the same way? Deep questions like these often seem unanswerable, especially in the elementary school classroom! But as we have seen, simple models can convey concepts and ideas with a power and scope that few people appreciate.
Don’t worry, we won’t create entire worlds from scratch, but we are going to use models and activities to demonstrate how the active environment of a solar system shapes and changes the surface of planets both suddenly, and gradually over long periods of time. The theory that things usually change gradually over time, but occasionally are radically transformed by titanic events is called punctuated equilibrium. There is a lot to learn about how the surface of the Earth and Moon got the way they are today, so let’s go exploring!
- 10.1: Modeling the Moon’s Surface in Clay
- We help students achieve this by guiding them step by step to create their own models. The idea is to get them to put into physical form something they have learned about the lunar surface, such as the large mountains that exist at the center of large craters! We do not have to produce great art in order to produce better understanding and comprehension for our students!
- 10.2: Dynamically Modelling The Moon’s Surface in Flour
- In the last activity, we pressed various size balls into a clay surface to make ‘craters’, depressions that were smooth and round, but not very exciting or dynamic. We’re going to take this up a notch and let kids see the crater making process as it happens! By dropping weights into pans of flour to look at the resulting craters, plus the ejecta – material which is blasted out of the crater on impact.
- 10.3: Exploring Crater Rays in Detail
- Things are completely different on the Moon; with no air, it doesn’t matter how much heat the impact generates, there will be no plume of dust and smoke because there is no air to rise and carry it aloft. Pulverized rock dust sprays out more like water from a hose, flying in perfect parabolic curves with no wind to disturb or distort its path. Modeling a single impact on Earth in your classroom requires a little ingenuity, but we can do it easily!
- 10.4: Dynamically Modeling The Lunar Surface in Plaster
- This activity will take a bit more preparation, and practice, than anything else we have done before. The practice involves timing, because wet plaster hardens quickly and if you start too soon, impacting rocks will simply disappear as though you’ve tossed them into a bucket of water – but wait too long and they will just bounce off the surface without affecting anything! You will need to try this on a small scale by yourself before you do the larger activity with students!