Earth-Moon Distance Activity
Materials:
World globe
Tennis ball
String or twine
Procedure:
1. With the tennis ball representing the Moon, ask students to place the
tennis ball at a distance from the globe that represents how far the Moon
is from the Earth.
2. Ask students to determine the circumference of the Earth and the distance
between the Earth and Moon by consulting a reference book. (Note: the
Earth’s circumference is about 25,000 miles and the distance between the
Earth and the Moon is about 240,000 miles.)
3. Ask students to divide the distance to the Moon by the circumference.
The answer is 9.6. Round it off to 9.5.
4. Compare the earlier estimate of the distance between the Earth and the
Moon with a measured distance based on the Earth’s circumference.
Wrap the string around the globe 9.5 times. Hold one end of the string at
the surface of the Earth and stretch the measured string across the
classroom. The other end of the string represents the distance of the
Earth to the Moon.
Discussion:
This activity provides a visual demonstration of the distance between the Earth
and the Moon. Relative positions of bodies in space are difficult to visualize
because of the enormity of the distances between them. Scale models provide
an opportunity to put meaning to astronomical numbers.
Extension:
Repeat the previous activity, only this time use the distance the ISS or shuttle
orbiter is in space. (Approximately 200 miles.) This time choose an area on the
globe that students are familiar with that represents the same distance. Students
will realize how close the orbit of the ISS is to the Earth, in comparison with how
far we traveled to the moon.