This simulation-based module demonstrates how the earth-sun-moon geometry gives rise to the phases of the moon as seen from earth. Initially, students explore a moon bisector demo to determine moon phase. Next, simulations provide perspectives of an observer looking down on earth and an observer standing on earth looking into the sky. Students can observe the path of the moon around the earth and see how the phases of the moon change. Instructor resources are available including student manuals, assessment materials, and a list of the assumptions used.

Editor's Note: This lab offers 3 animations and 3 interactive simulations to help students visualize lunar phases. The complete lab is appropriate for high school. Middle school teachers can select from the simpler animations.

This resource is part of a collection of digital astronomy labs.

Please note that this resource requires Flash.