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3rd Grade Science Core
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The Sky is Moving!...Not!

Earth rotates on its axis once every 24 hours, making day and night. Earth’s rotation also causes us to see changing star patterns in the sky. This was very confusing to early people. They thought that since it looked like the stars were moving, the sky must be revolving or rotating! We know that it is the Earth that is moving. The sky is not.

Try It!



  • Umbrella (a dark color works best)
  • Chair that spins
  • White paper
  • Tape
  • Friend


  1. Cut several different sizes of star shapes using the white paper.
  2. Open the umbrella.
  3. Tape the stars to the inside of the umbrella.
  4. Have your friend hold the umbrella high above your head while you sit in the chair.
  5. Now rotate or spin the chair counterclockwise.
    • Notice how you are rotating, and the stars above you are not.
Observe the night sky with a friend. Try to look at the same spot in the sky a couple of hours later than you looked the first time. Remember that Earth is rotating, not the sky.

Download the plug-ins: Get Adobe Acrobat Reader, and Get Quicktime Player. (The QuickTime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

  1. The title of the activity
  2. The URL (Internet address)
  3. Your name.

Remember that no pictures can be used that show student faces or student names on it. 

Teachers should view the Teacher Site Map to relate Sci-ber text and the USOE 3rd grade science core.

Updated October 24, 2008 by: Glen Westbroek

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