Phases of the Moon with a Lamp and Ball

Model lunar phases by moving a ball around you while facing a lamp that represents the Sun.

Materials

• Dark room
• Bright lamp (no shade)
• Small white ball on a stick

Steps

1. Stand with lamp at head height (Sun).
2. Hold ball at arm’s length (Moon) and turn in a circle.
3. Observe lit portion to identify phases; mark new, first quarter, full, third quarter.

What’s happening (the science)

• Phases depend on the Sun‑Earth‑Moon geometry, not Earth’s shadow (that’s an eclipse).
• The same half of the Moon is lit; we see changing fractions from Earth.

Safety & cleanup

• Do not stare directly into bright bulbs.
• Clear the floor to avoid tripping.

Tip: Extend this activity by asking students to measure, graph, or compare versions (e.g., different designs or variables).