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As you probably heard over the weekend, a large meteor entered the atmosphere and exploded over Russia last Friday morning. This hands-on activity will help your students grasp the likelihood that a meteorite will land at any given place on Earth—and perhaps ease their minds as well! (A student-facing version of this activity, with blue teacher notes and answers removed, is available as a downloadable PDF.)
Hands-On Activity: Will a Meteorite Land Near Me?
Inquiry Focus: Analyzing Data
Group Size: Pairs
Class Time: 30 minutes
Materials: globe that can rotate on its axis
Most globes spin on an axis supported by a curved metal meridian bracket running from the North Pole to the South Pole. Caution students not to get their fingers stuck between the globe and this metal meridian.
In this activity, one person will take the role of the “meteorite” and the partner will spin the globe. Halfway through the activity, you will swap positions.
1. Place the globe on a desk. If your globe has a metal support meridian running from north to south, make sure the meridian is on the side of the globe opposite the person acting as the meteorite.
2. The person acting as the meteorite should sit in front of the desk, within easy reach of the globe (about ½ meter away). Extend your index finger and move it to within a few centimeters of the globe. Close your eyes and wait for your partner’s instruction.
3. The partner should now gently spin the globe. [CAUTION: Spinning the globe too fast can cause injury.] Your target speed should be about one rotation per second. Once the globe is spinning, tell your partner, “Now.”
4. Keeping your eyes closed and upon hearing your partner say “Now,” the person acting as the meteorite should firmly place an index finger on the globe’s surface. This will cause the globe to stop spinning. [NOTE: Be sure to vary your approach angle to the globe. Come toward the globe from the top and bottom (the poles) as well as from the side. If you find it hard to stop the globe with one finger, use all your fingers to stop the globe but use the index finger as the marker.]
5. Once the globe stops spinning, leave your finger in place, open your eyes, and note the position of your finger. Assign this position to the appropriate column in a data table like the one shown below.
6. Repeat Steps 2–5 nine more times.
7. After ten trials, switch roles with your partner and repeat the activity.
8. Add the number of times your finger (the “meteorite”) landed in the four different location types in the data table. Determine the percentage of landings in each location. The percentage for each location is calculated by adding the number of landings (use the Totals row), dividing by the number of trials (should be 20), and multiplying the result by 100%.
- Ocean: _______________
- Continent: _______________
- Island: _______________
- My Hometown: _______________
1. Based on your results, what type of location is most likely to experience a meteorite landing?
Ocean locations should receive the most landings, followed by continents, and islands. It’s very unlikely that anyone will hit his or her hometown.
2. Why do you think the location in Question 1 received the most landings?
Sample Answer: Oceans make up the largest percentage of Earth’s surface, so it is more likely that meteorites would land in an ocean.
3. Do you think you would be more likely to witness a meteorite landing if you lived on a sailboat on the Pacific Ocean instead of living on land? Explain your reasoning.
Sample Answer: No. While it might seem that you would be more likely to witness a meteorite landing if you lived on the ocean, the fact is it doesn’t matter where you live. Assuming that meteorites can approach Earth from any direction, the chances that you would witness a meteorite are the same, no matter where you live.
How many natural objects fall to Earth each day? A quick look at the moon’s surface, especially the far side of the moon, provides proof—in the form of craters—that a very large number of meteorites have hit the moon’s surface. Since Earth’s surface is much larger than the moon’s surface, it’s reasonable to assume that even more meteorites have hit Earth. Why does Earth’s surface seem to have far fewer impact craters? Research this topic online and learn what protects Earth’s surface from meteor impacts… and how large a meteor or asteroid has to be in order to reach Earth’s surface.
Useful online resources are nasa.gov, National Academy of Sciences, and various university Web sites. For example, Harvard.edu has various resources about comets, asteroids, meteors, and meteorite impacts.