Moon Phases
Observe and describe the Moon's changing shape over about a month, recognising that it goes through a repeating cycle of phases from new moon (invisible) to full moon (complete circle) and back again
What a learner can do afterwards
- Describe that the Moon appears to change shape over about a month
- Name or draw at least three phases: new moon (dark), half moon, and full moon
- State that the pattern repeats: the Moon goes through the same shapes again and again
1 · Read
Look at the Moon on different nights. It does not always look the same. Its shape changes slowly, over about a month. Then it starts the same pattern again.
Emma looks at the Moon every night for a month. First it is dark. Then it is a half circle. Then it is round and full. Then it shrinks back to dark again.
Try to look at the sky at the same time each night. Watching for many nights helps you see the pattern change slowly.
The Moon changes shape each month, then starts the same pattern again.
More to read
Phases of the Moon
The Moon does not make its own light. It bounces back light from the Sun, like a mirror. That is why it glows at night.
Every night the Moon looks a little different. Sometimes you cannot see it at all. That is a new moon. It looks dark because the sunny side faces away from us.
A few nights later, a thin curve of light shows up. That is a crescent moon. It grows a little bigger each night.
About a week after the new moon, you see a half circle. That is a quarter moon.
The Moon keeps growing until it is one whole bright circle. That is a full moon.
Then it starts shrinking again. It goes back through a half circle, then a thin curve, then dark again.
The whole trip takes about one month. Then the Moon does it all over again, the exact same way, every single month.
The Moon and Its Motions
The Moon is Earth's only moon. It travels all the way around Earth about once a month.
A moon phase is the shape of the sunny part of the Moon that we can see from Earth.
When the Moon is a new moon, we cannot see it at all. It looks completely dark. This happens when the Moon sits between Earth and the Sun.
When the Moon is a full moon, we see the whole round circle glowing bright.
In between new moon and full moon, the Moon looks like a sliver, then a half circle, then almost round.
The Moon goes through all its phases again and again, about every 29 and a half days.
Phases and Motions of the Moon
After the Sun, the Moon is the brightest thing we see in the sky. But the Moon does not glow on its own. It shines because sunlight bounces off it, like light bouncing off a mirror.
If you watch the Moon every night for a month, you will see it change shape. This is called a cycle of phases.
First, the Moon disappears. That is a new moon.
Then a thin sliver appears and grows bigger each night.
Halfway through the month, the Moon looks like a full, round circle. That is a full moon.
After that, the bright part shrinks back down, night by night, until the Moon disappears again.
Is the Moon Growing or Shrinking?
The Moon travels around Earth. It takes about 27 days to go all the way around, but the phases we see take about 29 and a half days to repeat.
When more of the Moon lights up each night, we say it is waxing. Waxing means growing.
When less of the Moon lights up each night, we say it is waning. Waning means shrinking.
The Moon waxes from new moon all the way to full moon. Then it wanes from full moon back down to new moon. After that, it starts waxing again.
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2 · Watch
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Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.