Using spherical objects such as softballs, golf balls, and marbles, students build a more accurate conception of the distance between Earth and the Moon. Researchers have discovered that most people think Earth and the Moon are much closer to each other than they actually are. This misconception leads people to incorrectly conclude that the Moon must pass into Earth's shadow each month and that Earth's shadow causes the phases of the Moon.
Why Should My Students Do This?
If students hold misconceptions about distances, they may have difficulty discarding the belief that Earth's shadow causes the phases of the Moon. Beginning with an investigation of the Moon's distance from Earth helps students understand later that half of the Moon's surface is always lit.
What's Good about This Activity?
Students have a chance to articulate their beliefs and demonstrate what they believe is the correct size of and distance between Earth and the Moon before they learn the scientific point of view.