When a cosmic ray interacts with the Earth's atmosphere it creates secondary particles. These particles then interact in the atmosphere and create even more particles, which then create more particles and on and on. This process, called a {\it cosmic ray shower}, propagates through the atmosphere until eventually, some of the particles reach the ground.

This icebreaker activity involves putting together puzzle pieces to construct a representation of a cosmic ray shower.

Use this activity to peak interest and start a conversation about cosmic rays and cosmic ray showers. Break the audience into groups of three or four and have each group work on the puzzle together.

Ask each group what they think they are putting together a picture of. Some may have no idea, that is okay.

How might they know which way is up? Why do some of the lines stop midway?

Ask questions like these to get your audience wondering about cosmic rays. Then, visit the CHICOS classroom page for classroom activities related to cosmic rays and the CHICOS project.

Materials

• Cosmic Ray Shower Puzzle
• Cosmic Ray Shower Key
• Paper Cutter or Scissors

Puzzle Preparation

• Print the cosmic ray shower puzzle page.

• Make enough copies of this page to accommodate the number of groups you'll have.

• Fold the puzzle page down the middle as marked.

• Cut the page into five pieces where indicated by CUT HERE. Carefully trim each piece just above and below the black lines. Do not leave any white border.

• Cut each piece in two along the fold to make 9 total pieces (discard the bland white piece).