Star Trails

Star Trails

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Check out this picture of the night sky.

DISCUSS: What do you notice? How would you describe the stars?

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This photograph captures a moment in time--maybe a second or two. The camera’s shutter opened and closed quickly, letting in a little light.

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Here’s another photo of the stars.

DISCUSS: What do you notice?

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To make a photo like this, the camera’s shutter stayed open for 3 hours. Check out this sped up video of a similar photo.
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Get a See-Think-Wonder chart to record your ideas.

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THINK-PAIR-SHARE:

  • What do you observe in this photo of the night sky?
  • Do you notice any patterns?

Record your answers in the SEE column of your chart.

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THINK-PAIR-SHARE:

  • Why do you think there are bright streaks in the sky, rather than stars?

Record your answers in the THINK column of your chart.

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THINK-PAIR-SHARE:

  • What else do you wonder about this picture?

Record your answers in the WONDER column of your chart.

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For thousands of years, astronomers have observed the night sky and tried to explain what they saw.

In this activity, you’ll start with this photo of the sky and figure out what causes the streaks you see. Like astronomers before you, you’ll create a model that helps you explain what you see in the sky. After each Mystery, you'll add to or change your model as you get new ideas.

We'll walk you through it, step by step.

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Reveal answer

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Reveal answer

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Reveal answer

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Reveal answer

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Reveal answer

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Reveal answer

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Conceptual Model

Models are used by scientists to understand and explain something. A model is revised, or changed, as new information is learned.

There are many types of models, but you just finished creating a conceptual model.

A conceptual model helps scientists explain things that they can't see. After each Mystery, you will add the new things you've learned to your model.

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You've completed the Unit Starter!

Be sure to keep each student's Night-Sky Patterns accessible. They will use it after each Mystery in the Unit Connection.

Teach Mystery 1 next: How fast does the Earth spin?

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Activity Prep

Print Prep

THIS LESSON WAS REVISED ON SEPTEMBER 17, 2019. Here is the previous version.
Note: This lesson is part of this unit’s Anchor Layer. If you have the Anchor Layer turned on, we recommend teaching all lessons in the remainder of this unit in order.

The anchor phenomenon for this unit is star trails that appear in long-exposure photographs. Students generate observations and questions about the phenomenon and create an initial model to explain what causes these patterns to form.

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