Moon Phases

Growing and Shrinking

The Moon does not really grow or shrink, but it can look different from night to night. Sometimes we see more of its bright side, and sometimes we see less. Learning moon phases helps children notice patterns in the sky. It also builds early science skills like observing, comparing, and describing change.

The Moon shines because sunlight lights it up. As the Moon moves around Earth, we see different amounts of the lit part. When the bright part gets bigger, we say the Moon is growing. When the bright part gets smaller, we say the Moon is shrinking.

Key Facts

The Moon can look different each night.
Growing means we see more light.
Shrinking means we see less light.
The Moon does not make its own light.
Sunlight lights up the Moon.
Moon phases follow a repeating pattern.

Vocabulary

Moon phase: A moon phase is the shape of the Moon we see in the sky.
Growing: Growing means the bright part of the Moon looks bigger each night.
Shrinking: Shrinking means the bright part of the Moon looks smaller each night.
Light: Light is the bright part we can see on the Moon.
Pattern: A pattern is something that happens again and again in the same order.

Common Mistakes to Avoid

Thinking the Moon makes its own light, but the Moon looks bright because sunlight shines on it.
Thinking the Moon is really changing size, but only the bright part we can see seems to grow or shrink.
Thinking growing means the whole Moon moves closer, but growing only means we see more of the lit side.
Thinking shrinking means the Moon is disappearing forever, but the phases repeat in a pattern and the Moon comes back to fuller shapes.

Practice Questions

1 On Monday you see a small bright Moon. On Tuesday you see a bigger bright part. Is the Moon growing or shrinking?
2 A child watches the Moon for three nights. Each night the bright part gets smaller. What word tells this change?
3 Why can the Moon look like it is growing and shrinking even though the Moon itself stays the same size?