Why does the Moon change shape?
1Read
The Moon does not make its own light. It only reflects light from the Sun, like a mirror.
Half of the Moon is always lit by the Sun — the half facing the Sun. But as the Moon travels around the Earth, we see different amounts of that lit half.
When the Moon is between the Earth and the Sun, the lit side faces away from us. We see nothing — a new moon. Two weeks later, the Earth is between the Sun and the Moon, and we see the whole lit side — a full moon.
In between, we see slices: a thin crescent, a half moon, a big gibbous moon. The Moon takes about 29 and a half days to go through all its shapes, which is where the word ‘month’ comes from.
2Words to learn
3Check your understanding
4Explain it
Speaking challenge
Describe the shape of the Moon tonight and explain why it looks that way.
Say it out loud. Nobody is listening — that’s the point. Mistakes are allowed.