Get ready—the moon is about to join the Earth’s cosmic dance with the sun. Along the way you'll out how the moon’s rotation and revolution create awesome patterns that keep us moon-gazing day and night.
Watch this animation to learn about the moon’s phases. Then answer the questions in the Take Notes box below.
Need help? You might want to check the definitions of specific vocabulary terms. In addition to the glossary words you’ve already learned, the terms new moon and full moon will also be used. You may pause the animation, rewatch it as many times as you like, and read the transcript.
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The moon is like a giant mirror in the sky– it is always reflecting light from the sun. But from our perspective on Earth the moon seems to change.
That’s because, as we rotate daily and revolve around the sun yearly, our moon makes a trip around us once a month. And this revolution around us is what causes the predictable patterns of reflected light and darkness on the moon that we call phases: “New” to “Full” to “New” again takes a month.
And the moon isn’t just visible at night. In fact, for much of its orbit we see it during the daytime- and that is because it is passing us on our sun side.
As it revolves around us, the moon also rotates just once on its axis. Its revolution around Earth matches its rotation. This means we only see one side of the moon but the sun gets to see its face and its –ahem– backside.
So look at the bright side, and if you can’t see it just wait awhile, and it’ll come back around.
1) Explain the relationship between rotation and revolution of the moon.
2) How do the moon's rotation and revolution affect what we see from the Earth?
3) Describe the different phases of the moon and the patterns of reflected light and darkness associated with each phase.
4) Why can we only see one side of the moon?