Ask them to draw the equator and then to draw an approximate outline of their continent and place a dot roughly where they live. Refer to the globe as needed.
Review the causes of day and night (see The Cycle of Light).
Invite the children to experiment with their Styrofoam Earth and flashlight Sun to “explain” differences in daylight length through a year. One child will hold the Sun and another will slowly move Earth around it. The other children in the group will evaluate the results and suggest model changes.
Draw the children's attention to the north polar region, where day and night differences throughout the year are extreme. They may be familiar with the fact that the north pole experiences months of darkness in the winter and months of daylight in the summer.
Simply spinning on our axis (rotating) does not explain months of darkness or light at the poles. The long polar night and day cycles also can help the children fix the direction of the axis so it points consistently in a single direction for the movement of Earth around the Sun.
Invite the groups to demonstrate their models to show that the annual pattern of changing day length on Earth is caused by Earth's annual revolution around the Sun with its axis pointing to a fixed position in space.
For groups of 2 to 4 children
Connections to the National Science Standard(s)
Standards A&D (grades 5–8):Understand and communicate the scientific explanation of how objects in the solar system have regular and predictable motion, such as the apparent daily motion of the Sun in the day/night cycle, and annually across seasons.