You will need
- Tape measure
- A4 paper
- Pens or pencils
- Sand or flour
- Cocoa powder
- Gardening drip trays
- Small round objects of all sizes, like marbels, pebbles or golf balls
- Footstool, as needed
Before you begin
- Set out equipment around the meeting place for groups. Each group will need a set of the items listed above.
- Discuss meteorites and craters and find out how much everyone already knows about them.
- Split everyone into small groups and have each group wait by a set of equipment. Explain that they’ll be recreating a meteorite impact. Each group should draw a table to record their findings, with four columns. Label the column at the top: ‘Height’, ‘Object used’, ‘Crater width’ and ‘Crater depth’.
- Each group should fill up their drip tray with sand or flour. They should create an even layer about 4cm deep.
- Sieve a thin layer of cocoa powder onto the layer of sand or flour. This should make it easier to see the crater on the surface of your new planet.
- Choose an item to drop onto the planet from above. Write down the name of the object on your table. Choose a height to drop it from, measure and then record this too.
- Drop the object and examine the crater it makes on the surface of your planet. Record the depth and width of the crater on your table, then remove the object.
- Repeat this for all of the round objects you have available. Record the details for each one in the same way. You may need to replace your layer of cocoa powder after a while.
- Everyone should come back together to share their findings. See if anyone got similar or wildly different results. Compare measurements to see what difference the height of the drop made to the dimensions of the crater.
When you look at the moon, even from Earth you can see the craters caused by all the impacts with different meteorites over the years. These craters change the moon's appearance and can also cause smaller meteors to break off the surface. Why might it be useful for scientists and geologists to study the impact of meteorites on the moon? Remember that Earth’s atmosphere is very different and far more resistant to meteorite strikes.
It’s fairly straightforward to recreate the impact of meteorites with round objects and a fine layer of sediment. What impact did the size of the objects and the height they were dropped from have on the shape and depth of your craters? Heavier objects should produce deeper craters, while lighter objects will create shallow craters. The larger and heavier the object, and the greater the height it falls from, the bigger the crater.
Supervise young people, and only do science activities that are advised and age appropriate for your section. Test activities first, to make sure you’re confident you can lead them safely. Use protective clothing where necessary.
Check for allergies before you begin. Make sure you have suitable areas for storing and preparing food and avoid cross contamination of different foods.