Make Impact Craters
In this science experiment, kids make impact craters like the ones on the Moon!
The Moon’s surface has three main features: plains called maria, highlands called terrae, and craters.
The maria are the dark areas we can see from Earth. Early astronomers thought they were full of water, so they called them “maria,” which is the Latin word for seas. But we now know that these dark areas are actually full of solidified lava.
The terrae are mountains that have been pushed up along the rims of craters.
The craters are the most obvious features on the Moon’s surface; there are literally millions of them. They measure from about 1 mile to 700 miles across. Unlike the Earth, the Moon has no atmosphere to provide protection from asteroids, comets and meteoroids. So the Moon has been hit many, many times! The surface of the Moon is covered by a fine, gray dust called regolith; this is the result of this constant bombardment, which reduces lunar rocks to dust.
This experiment involves dropping objects into a bowl of flour, which could result in the flour spraying upwards into a child’s eyes. Precautions should be taken to avoid this — either by warning children not to put their face too close to the bowl, or by providing them with goggles.
- Plastic bowl - 1 per student
- Flour - enough to fill the bowl least halfway - 1 per student
- Marble - 1 per student
- Bouncy ball (larger than magnetic marble) - 1 per student
- Ruler - 1 per student
- Goggles (optional) - 1 per student
Add flour to the bowl until it is about halfway full. (We use flour instead of sand or soil because the flour is more like dust and allows for greater definition when the craters are made.)
Use the ruler to measure a distance approximately 6" from the surface of the flour. Drop a marble from this height into the flour. What happens?
Remove the marble and repeat the experiment, except drop the marble from 12 inches. How does your crater look now?
Now try using a larger bouncy ball, and drop it again from 6 inches, then 12 inches.
How do the sizes of these craters compare to the craters made by the marbles? The craters on the Moon are different because of variations in the size of what hit, how fast it was moving, and what was on the Moon’s surface where it hit.
Make a larger tub of flour and use larger balls!