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Spaceship Earth    Mystery 5

Mystery 5 image

This Mystery explores why the Moon seems to change shape (phases) over the course of a month.

Beginning Exploration (1 of 20)
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Beginning Exploration (2 of 20)

DISCUSS:
What do you notice about the Moon each night? (1 of 14)

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Beginning Exploration (3 of 20)

DISCUSS:
What do you notice about the Moon each night? (2 of 14)

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Beginning Exploration (4 of 20)

DISCUSS:
What do you notice about the Moon each night? (3 of 14)

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Beginning Exploration (5 of 20)

DISCUSS:
What do you notice about the Moon each night? (4 of 14)

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Beginning Exploration (6 of 20)

DISCUSS:
What do you notice about the Moon each night? (5 of 14)

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Beginning Exploration (7 of 20)

DISCUSS:
What do you notice about the Moon each night? (6 of 14)

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Beginning Exploration (8 of 20)

DISCUSS:
What do you notice about the Moon each night? (7 of 14)

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Beginning Exploration (9 of 20)

DISCUSS:
What do you notice about the Moon each night? (8 of 14)

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Beginning Exploration (10 of 20)

DISCUSS:
What do you notice about the Moon each night? (9 of 14)

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Beginning Exploration (11 of 20)

DISCUSS:
What do you notice about the Moon each night? (10 of 14)

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Beginning Exploration (12 of 20)

DISCUSS:
What do you notice about the Moon each night? (11 of 14)

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Beginning Exploration (13 of 20)

DISCUSS:
What do you notice about the Moon each night? (12 of 14)

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Beginning Exploration (14 of 20)

DISCUSS:
What do you notice about the Moon each night? (13 of 14)

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Beginning Exploration (15 of 20)

DISCUSS:
What do you notice about the Moon each night? (14 of 14)

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Beginning Exploration (16 of 20)
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Teacher Note: Some calendars and websites refer to the "half moon" phase as the "quarter moon" instead. We have deliberately adopted the more straightforward and descriptive name, "half moon," and we encourage you to do the same!

The term "quarter moon" refers to the idea that the moon has completed one-quarter of its circular orbit (starting from "new moon"). This is simply an old linguistic convention, and it's worth noting that none of the other names for phases are based on this logic; for example, no one calls a full moon the "two-quarters" moon. All of the other phase names (crescent, gibbous, full) instead describe how the moon looks.

"Quarter moon" does appear as the dominant phrase on many websites and non-fiction resources, but there is no official scientific naming convention regarding moon phases. We hope you'll join us in being a trendsetter. Let's make the names of moon phases more straightforward and consistent! :)

Beginning Exploration (17 of 20)

DISCUSS:

Before you start the activity, discuss as a class: what ideas do you plan to test to see if you can create the Moon’s phases and make them go in order?

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Beginning Activity: Re-create the Moon's phases
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Beginning Activity: Model the Moon's Phases
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Beginning Exploration (18 of 20)

Check out the video in the next slide to see your Moon phase model compared side-by-side with the real sky!

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Beginning Exploration (19 of 20)
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Beginning Exploration (20 of 20)

DISCUSS:

Now that you've learned what causes the Moon's phases, how would you explain it to someone who doesn't know?

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Beginning Complete!

You've completed the Exploration & Activity!

If you have more time, view the assessment, reading and extension activity in the optional extras.

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Optional Extras

Below are ideas for extending this topic beyond the activity & exploration which you just completed.
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Activity: The Moon's Face

Encourage creative storytelling by asking your students to look for pictures on the Moon's face using this activity from the Lunar and Planetary Institute. For photos showing what various cultures have seen on the moon, check out this National Geographic article

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Animation: The Phases of a Tree

Ordinary objects have phases, like the phases of the moon. But usually we don't even notice these changes in lighting.

You and your class can see how this works at Dr. Cecilia Barnbaum’s Astronomy Demo Site. Click on "Moon Phases" to see the phases of a tree and a ball in the sunlight.

Hit the play button to start the animation. There is no narration, so we suggest you pause to talk with your class about what the animation is showing. When is the tree a "crescent tree"? When is it a "half tree"? Watch the animation all the way through to see all the phases.

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Image & Video Credits

Mystery Science respects the intellectual property rights of the owners of visual assets. We make every effort to use images and videos under appropriate licenses from the owner or by reaching out to the owner to get explicit permission. If you are the owner of a visual and believe we are using it without permission, please contact us—we will reply promptly and make things right.

Exploration
Venus & the Moon by Claude.schneider , used under CC BY-SA / cropped, adjusted color, added border
moon rising by flowcomm , used under CC BY / cropped, adjusted saturation, layered with another image
reaching for the moon by Sivaprasad k S / spliced
full moon by Krückstock , used under CC BY-SA / adjusted saturation
harvest moon rising by slworking2 , used under CC BY / adjusted color and speed
moon in daylight by Zeynel Cebeci , used under CC BY-SA / adjusted color and cropped
moon in sky by Bill Johnston / cropped, layered with other imagery
crescent gibbous moon by Thomas Bresson , used under CC BY / Heavily modified
crescent moon by P. Bramwell / Heavily modified
moon view by Luc Viatour , used under CC BY-SA / Heavily modified
house at night by StruffelProductions / cropped
sunrise background by Stellarium / Heavily modified
tablet by simon-ho / Heavily modified
lightbulb by KMJ , used under CC BY-SA / Heavily modified
Earth by Celestia / part of a diagram
Other
crescent moon by Richard Flink , used under CC BY-SA / cropped, adjusted color