Moon phases model with a ball and lamp, grades 6–8
What it is: a middle school modeling activity where each student holds a ball on a stick at arm's length and turns slowly in a dark room with one lamp as the Sun. The lit part of the ball changes shape as it moves around their head, and students sketch and name each phase. It shows that phases come from how much of the Moon's sunlit half we can see, not from Earth's shadow.
Time: about 35 minutes. Grade: 6–8.
Materials: a lamp with an LED bulb and no shade, foam or plastic balls about 7 cm wide on craft sticks or pencils (one per student), a phase sketch sheet with eight circles, and a room you can darken.
- Ask: "Why does the Moon change shape?" Write the ideas, including "Earth's shadow", and come back to them at the end.
- Place the lamp in the center at head height. Students stand in a circle facing it, holding the ball at arm's length (their head is Earth).
- Ball in front of the lamp: students see the dark side. This is the new moon.
- Students turn slowly to the left (counterclockwise), keeping the ball in front of their face. Stop at each eighth of a turn and sketch: crescent, first quarter, gibbous, full.
- Keep turning to see waning gibbous, third quarter and waning crescent.
- Ask: "Was Earth's shadow (your head) on the Moon during the phases?" Only rarely, at full moon, if you line up exactly: that is a lunar eclipse.
- Share the NASA fact: a full cycle of phases takes about 29.5 days.
Safety: use an LED bulb, which stays cool, tape the cord to the floor, and keep the circle wide so no one bumps the lamp.
Differentiation: students who need support sketch four main phases only. Students who are ready explain why we do not get an eclipse every month (the Moon's orbit is tilted a little). English learners can label phases in a word bank.
Quick check: ask a student to show with the ball where the Moon is during a first quarter and explain why half of it looks lit.
For more ideas at this grade, browse the other free activities on the Hub.
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About this resource
- Shared by
- @UpOnlyLearning · Curriculum team
- Posted
- Oct 31, 2026
- Type
- Lesson plan
- Grade
- Grades 6–8
- Subject
- Science
- Language
- English
- License
- Free for classroom, co-op and tutoring use. Please don't resell.