Students often do not understand lunar phases or eclipses. Even those with a minimal understanding often get them confused. By having models of both in the same sketch can help the students understand both phenomena.
The upper right figure shows the moon in orbit around the earth and the resulting phase of the moon to its left; This assumes that the sun's rays originate very far to the right.
The large shadow of the earth can be moved towards the moon, indicating the progress of the lunar eclipse. Since the sun is not "inifinitely" far away, the earth's shadow is actually a bit fuzzy around the edges and the size of the shadow is slightly smaller than the size of the earth.
