What can you learn from a crater? In this activity, you’ll simulate asteroid impacts with paint to find out what scientists can learn about the moon’s history and surface from its craters.
Age: 4 - 10
Time: 20 - 30 minutes
Topics: moon, crater, asteroid, model
What you need:
- An outdoor location (or large sheets of plastic or paper to protect the floor indoors)
- Washable craft paint, 3 different colors
- Large sheets of chart paper, newspaper or butcher paper, (about 2 ft. x 2 ft.)
- Cotton balls
- Plates or shallow containers for holding paint
- Stopwatch or timer
What to do:
1. Start by doing some research about craters. Find several pictures of different areas of the moon (or other planets with craters) and make some observations about what you see.
- What sizes and shapes are the craters?
- Are there a lot of craters, or only a few?
- What other differences do you notice between the pictures?
2. Since the moon is very large and far away, you’ll be doing what scientists do when they want to study something that is too large, complicated, or far away to study directly: you’ll use a model. A piece of paper will represent the moon’s surface, and cotton balls dipped in paint will represent asteroids striking the surface to create craters.
3. This model can get messy, so it’s best to do it outdoors if you can. If not, make sure to cover the floor of your work area with paper or plastic to catch any paint splatters.
4. Place a large sheet of paper on the ground or floor. (If you’re outdoors, you might want to weigh down the corners, so it doesn’t blow away.) This is the surface of your “moon.”
5. Add one color of paint to a plate or container that you can easily dip a cotton ball into. To create an “asteroid” impact, coat the cotton ball in paint, stand near the edge of the paper, and drop or throw the cotton ball down onto the paper. Pick up the cotton ball (trying not to smudge the paint mark) and reuse it for the next impact. Practice a few times and experiment with different techniques, like throwing the cotton ball forcefully toward the paper instead of dropping it OR dropping it with your hand held up high instead of held out straight. Make some observations about the paint “craters” you made:
- How do they look the same as or different from the pictures of actual moon craters?
- How do the “craters” look different if you throw instead of drop? Or if dropped from a different height?
6. Put out a clean piece of paper. Set a timer or stopwatch for 20 seconds. Start the timer and create as many paint craters on the paper as you can until the time is up.
7. Put a second color of paint into a clean container get a clean cotton ball. Set the timer for 20 seconds again and create craters (on the same paper) with the new color until time is up.
8. Choose a third paint color and repeat step 7. Then make some observations about the “moon” surface you created. Here are some questions to think and talk about:
- Are there any craters that are on top of each other?
- Which color is on top? How can you tell?
- What shapes are the craters when they are partly underneath another one?
- How is this model like the craters on the Moon? How is it different?
- How could we tell which craters on the Moon happened first and which came later?
9. Other ideas to try:
- Repeat the activity with a new piece of paper, but set your timer for 60 seconds each time instead of 20. How does this “moon” surface look different from your first one? What do you think that might mean for parts of the moon where there are lots of craters, and parts where there are only a few craters?
- Become a Crater Detective: Have a friend create their own impact paintings and share them (or photos of them) with you. What can you figure out about how their “moon’s” surface was formed? Which craters are the oldest (made first), and which are the newest (made last)? Can you tell if the “asteroids” were moving fast (thrown hard) or slowly (dropped gently)? Do you think their drop time was closer to 20 seconds or 60 seconds?
Craters happen when an asteroid (large space rock), meteoroid (smaller space rock), comet, or other space object crashes into a planet’s or moon’s surface. The collision throws out rocks and dust from the surface, leaving a circular rim and sometimes rays of debris radiating out from the crater.
The Moon is covered with craters—some as large as the state of Texas and some smaller than the tip of a pin. Since the Moon has no wind or water to wear away the craters over time, their shapes can stay unchanged for billions of years—or until they are interrupted by another impact!
Scientists use crater patterns to learn about the age of a planet’s surface and find out when different impact events happened. The more craters a surface has, the older it is. Young craters have crisp rims and lie on top of other craters. Older craters have softer rims, and their debris and rays may be covered with fresh craters. Scientists use some of the same observations you did — such as which circle is on top (superposition) or which spines or rays are interrupted (crosscutting of features) — to determine which crater happened first, second, third, and so on.
Models, like the one you used here, are important tools for understanding parts of the world that are too big, too small, too far away, or too complicated to understand directly. A good model should be similar to the system it is modeling in important or useful ways; however, a model will also have aspects that behave differently or do not match the actual system.