This interactive tutorial features an inquiry-based approach to promote understanding of moon phases. Part of the Astrophysics Science Project Integrating Research and Education (ASPIRE), the tutorial opens with a diagram of the Earth-Moon system. The user "spins" the Earth, then determines which sections of Earth and Moon are receiving sunlight. In Part 2, users investigate how sunlight reflecting off the Earth is related to moon phases. The animation divides Earth into 8 sections and places the direction of incoming sunlight. Using only the images in the diagram, students must correctly label the moon phases. Part 3 puts everything together as Moon orbits around Earth.

Editor's Note: In the spirit of true inquiry, students will require time to explore this simulation. Expect younger students to have some confusion about the waxing and waning nature of moon phase changes. Older students will get it more quickly, but still need time to process how lunar phases depend upon the observer's position and reflection of sunlight. This struggle is necessary, but should produce some "aha" moments.

This resource is part of ASPIRE, an interactive lab project designed to be visually attractive and fun, yet mentally challenging for students in grades 6-9. Materials include complete lesson plans authored collaboratively by teachers and research scientists. See Related Materials for a link to the full collection.

Please note that this resource requires Flash.