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Videos: Watch this Demo

Description: This demonstration illustrates how craters are formed by colliding masses.


  • Sand box
  • Various size metal balls
  • Small 12V light bulb
  • DC power supply
  • Video camera on tripod
  • Something flat, like a block of wood
  • 2 Banana plug cables

Setup Procedure:

  1. Smooth the sand using something flat, such as a block of wood.
  2. Place the light bulb inside the sand box in a corner.
  3. Set the light to about 9V.
  4. Setup the video camera to the AV equipment and position to look at the sand box.

Demonstration Procedure:

  1. Turn on the power supply.
  2. Drop a metal ball from a few feet up (about as high as you can reach).
  3. Note the size and shape of the crater.
  4. This may be repeated with different size balls or from different heights.