Phases of the Moon


Sara Papsidero

Pace High School, Manhattan

Summer Research Program for Science Teachers

August 2007



Unit: Astronomy


Duration: 1 period; two week field work project


Aim: How are the motions of the Earth, the moon, and the sun, related to the moon’s phases?









Do Now: Why does the moon seem to change shape?


Demonstration: Model the following activity for students.



1.     Working with a partner, have one person hold a ball in front of a source of light.  Pretend the ball is the moon and the students, standing side by side, are the Earth.  While one student is holding the moon, both students should begin to rotate so that the moon ‘revolves’ around them. When the moon is in between the sun and the Earth, the ball should look dark (new moon). Note when you see the different phases of the moon. The first student should sketch how the moons lighted portion changes it revolves around Earth.


2.     Discuss why we see different moon phases. 


3.     Discuss how waxing means for the lighted part to grow, and waning means for the lighted part to shrink.


4.     As a class, create a diagram on the overhead of the 8 moon phases from class observations.  Understand how the phases are cyclical.


5.     Discuss and create the journal students will use to observe the moon for two weeks.


6.     On the first page of the journal create a diagram showing the 8 phases of the moon.




Waxing, waning, gibbous, crescent, phases



Begin observing the night sky.





Earth Science Standard 4 - Key Idea   1.1