The activity is in the second in three quarter sequence of science classes for non-science instructors. It could be anywhere in the course sequence.

I introduced these at a meeting of the American Association of Physics Teachers a while back and since then I have received emails from an increasing number of high school teachers that have started using them having heard about them by word of mouth. The high school teachers report spending more time with them than Bob and I do in our college class (typically over a week compared with a day or two in our class).

Students will understand how the rotation of the moon around the earth and the rotation of the earth around the sun affect the phases of the moon.

• Develop students' conception of three-dimensional relationships in nature.
• Develop students' knowledge of planetary mechanics.
• Encourage students to search for scientific explanations for common natural phenomena in their everyday life.

Created by Keith Clay at GRCC, this series of five interactive animations illustrates the 'phases of the moon' and the associated sun-earth-moon configurations. Students observe the Moon for about six weeks prior to working with the animations. The animations allow the students to observe and play with the rates of rotation and revolution between the earth and moon, and change the sun-earth-moon configurations to see the resulting moon phase. Links to pdf versions of the handout and a form to record moon observations are included.

A written set of exercises leads students through examination of the animation series. By using a lamp, a ball, and the viewer's head to represent the sun, moon, and earth respectively, students recreate the configurations shown in the animations and observe/sketch the phases of the 'moon' as depicted on the ball lit by the lamp. Additional animations and exercises are provided.