The Sun is a star: a 5th grade flashlight brightness activity

1. Ask: "Is the Sun a star?" Take a quick vote and keep the answers on the board.
2. Mark spots on the floor at 2 meters and 10 meters from the viewers. Darken the room.
3. Trial 1: hold the two identical flashlights side by side at 2 meters, pointed at the wall near the viewers. They look the same.
4. Trial 2: move one to 10 meters. Students describe what changed. The light did not get weaker; it is farther away.
5. Trial 3: put the weaker light at 2 meters and a strong light at 10 meters. Ask: "Which looks brighter? Does that tell you which is really stronger?"
6. Connect to space: the Sun is about 150 million kilometers away, and every other star is far, far beyond that. Revisit the vote.
7. Students write a claim with evidence: "The Sun looks brighter than other stars because ___."

Safety: point lights at the wall, never into anyone's eyes, keep walking paths clear in the dark, and turn the room lights back on between trials.

Differentiation: students who need support compare only trials 1 and 2. Students who are ready add a third distance and rank the brightness. English learners can use "Closer lights look ___."

Quick check: ask: "Two stars look equally bright. Does that mean they give off the same amount of light? Why or why not?"

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