A lunar eclipse happens when Earth moves between the Sun and the Moon, blocking sunlight from reaching the Moon. A classroom model with a flashlight, an Earth ball, and a Moon ball helps you see this alignment in a simple way. The flashlight represents the Sun, the Earth ball casts a shadow, and the Moon ball shows where that shadow lands.
This project matters because it turns an event in space into something you can build, test, and explain.
Key Facts
- Lunar eclipse alignment: Sun, Earth, Moon in a nearly straight line.
- The flashlight represents the Sun, the Earth ball represents Earth, and the small ball represents the Moon.
- A shadow forms when an object blocks light from a source.
- A lunar eclipse occurs when the Moon passes through Earth's shadow.
- The darkest part of a shadow is called the umbra, and the lighter outer part is called the penumbra.
- Scale ratio example: if Earth is 4 times the Moon's diameter in the model, then Earth ball diameter = 4 x Moon ball diameter.
Vocabulary
- Lunar eclipse
- A lunar eclipse is an event in which the Moon moves into Earth's shadow.
- Shadow
- A shadow is a dark area made when an object blocks light.
- Umbra
- The umbra is the darkest central part of a shadow where the light is fully blocked.
- Penumbra
- The penumbra is the lighter outer part of a shadow where the light is only partly blocked.
- Alignment
- Alignment means placing objects along the same straight line or path.
Common Mistakes to Avoid
- Putting the Moon between the flashlight and Earth, which models a solar eclipse instead of a lunar eclipse.
- Using a room with too much light, which makes the shadow hard to see and can hide the eclipse effect.
- Placing the Earth and Moon balls at different heights, which can make the shadow miss the Moon even when the objects look close together.
- Thinking every full Moon causes a lunar eclipse, which is wrong because the Moon's orbit is tilted so it usually passes above or below Earth's shadow.
Practice Questions
- 1 A model uses an Earth ball with a diameter of 12 cm. If the Moon ball should be about one-fourth as wide as Earth, what diameter should the Moon ball be?
- 2 The flashlight is 60 cm from the Earth ball, and the Moon ball is 20 cm beyond Earth in a straight line. How far is the Moon ball from the flashlight?
- 3 In your model, the Moon ball is not darkening even though the flashlight is on and Earth is in front of it. Explain two adjustments you could make to help Earth's shadow fall on the Moon.