by Beth Napier
As explained in the Introduction section of this lesson, the path in the sky defined by the apparent motion of the Sun against the background stars (which is actually the plane of the Earth's revolution about the Sun) is called the Plane of the Ecliptic. This demonstration should help to explain to your students the concept of the Plane of the Ecliptic:
Bring in an aluminum pie pan or other flat, round container with a rim. Also bring some clay or play dough and a few marbles.
The students should get the idea that if one were to look at the solar system from its outer edges, we would see that the planets revolve on a particular plane (the pan) and along a particular path (along the almost circular tracks).
Have students name the planets and indicate the Asteroid Belt on Figure 1: "The Plane of the Ecliptic."
Have each student answer the following questions:
Have your students describe, in writing, how this demonstration depicts the Plane of the Ecliptic. Encourage the students to experiment with the demonstration as they work on their compositions.