High school students should have a clear understanding of why the seasons occur and should be able to articulate this concept to others. This lesson reinforces this knowledge by having students review the basics of the seasons and design their own monuments to keep track of and commemorate the seasons. In the process students will review their understanding of the science behind the seasons, learn some theories about Stonehenge, Medicine Wheel, and other monuments, and reflect on their own culture's methods of commemorating the passing of the seasons.

Geography, earth science, history

Standard 7: "The physical processes that shape the patterns of Earth's surface"
Standard 17: "How to apply geography to interpret the past"

Two to three hours

• Computer with Internet access
• Writing and drawing materials

Students will

• identify the reasons people throughout time have kept track of the seasons and how modern society keeps track of the seasons;
• review and answer questions about the scientific reasons why the seasons occur;
• research and take notes on ancient monuments that may have served as astronomical calendars; and
• design astronomical monuments that keep track of the seasons and that showcase how modern society acknowledges the seasons.

Ask students to describe some of the reasons why, throughout history, people have kept track of the sun's path and other astronomical phenomena related to the seasons. Do they think this is still important? How do people in our modern culture keep track of the seasons? Is it necessary to know the time of the sunrise and sunset or the angle of the sun on a given day? Who in our society might still be highly interested in these facts? Discuss these questions as a class.

Tell students that they are going to design their own monuments to the seasons. The monuments will be placed in a prominent location in their community and will serve the dual purposes of tracking the seasons and commemorating different seasonal traditions in their culture. Inform them that they will first need to review their knowledge of the science behind the seasons and brainstorm how this understanding can be demonstrated in a clear and interesting way to members of their community.

Have students use the A Reason for the Season activity and the Web sites below to review the science behind the seasons. As they look at the sites they should take notes to answer the questions below the list of links:

To Every Season There is a Reason
World Book: The Seasons (very basic, easy reading)

Questions:

• What is the general process that causes the seasons?
• Is the Earth closer to the sun in the Northern Hemisphere's winter or summer?
• What is the relationship between the Earth and the sun during each of the four seasons in your home region?

Ask students to visit the Web sites below to learn about some ancient and modern monuments that may have served as astronomical calendars. As they look at the sites, they should take notes to explain how these ancient monuments may have kept track of seasonal changes, citing specific examples of how the monuments' structures allowed people to track the seasons. (Point out that it's not certain that these monuments were used as astronomical calendars or to track the seasons, but that, for the sake of this assignment, they should focus on the theories proposing that the monuments did serve these purposes; the goal is to see how such a monument could be constructed rather than to determine the verity of one particular theory).

Astronomical Calendar
Mid-Atlantic Geomancy: Orthographic Projection Index
Sacred Places: Stonehenge
Stone Wheels and Dawn Stars Rising

In groups or individually, have students brainstorm the types of monuments that they might design. They should think about how the monuments can keep track of the progressions of seasons while simultaneously showcasing or commemorating some of the ways in which their culture celebrates or commemorates the changing of the seasons. Emphasize that their monuments will therefore be part scientific models and part works of art.

Ask students to design their monuments on paper, diagramming their shape, location, and structure and clearly showing how the monuments will keep track of the progression of the seasons.

The students will probably need to add text captions to their diagrams; depending on the amount of text needed, they may want to use additional pieces of paper to accompany the diagrams. They should also draw and explain the features of the monument that will showcase modern seasonal celebrations (the "art" part of the monument).

Have students share their monuments with the class.

• Have students look more closely at the Astronomical Calendar and write paragraphs explaining in detail what this model shows.
  
  
• Have students research the opposing viewpoints concerning the original purposes of Stonehenge, Medicine Wheel, or another ancient monument that may have been used for astronomical measurements. What are the different opinions, why do people disagree on these issues, and is it likely that we'll ever know the truth?
  
  
• Have students read about the process by which scientists (and students) can deduce the cause of the seasons at To Every Season There is a Reason.

National Geographic: Xpeditions Activity—A Reason for the Season
To Every Season There is a Reason