Phases of the Moon: How to determine cyclically changes of the visible lunar surface

Have you ever noticed that regardless of which place on Earth we are, we all see the same shape of moon on the same day? Have you ever noticed that the illuminated part of the moon changes sequentially and cyclically?

In this teaching unit, we’d like students to understand how the relative positions of the sun, earth and moon influence each phase of the moon, how to determine this phase for a given day, and how to calculate the percentage of its illuminated part.

This unit is recommended for students age 14 to 16 years as prior knowledge in trigonometry and astronomy is required.

Authors: Cristina Viñas Viñuales (ES), Ederlinda Viñuales Gavín (ES) | Ed. Science on Stage Deutschland e.V. | License: Creative Commons