Once students have mastered the above, distribute Shadow Pattern 4A. Ask them to determine the direction of the sun in the sky if they were on the surface of the planet, and the nature and shape of the surface features casting these shadows. Write their hypotheses on the board and discuss. Distribute copies of Shadow Pattern 4B. Explain that this is an image of the same region on the planet but taken about 12 hours later. Ask students to determine the direction of the sun if they were on the surface when the image was taken. Tell them to examine this image and compare it to the one taken 12 hours earlier.
Teams can verify each others' models.
Distribute copies of Shadow Pattern 5A and again ask teams to determine the direction of the sun in the sky and guess the shape and nature of the surface features casting the shadow. After various possibilities are formulated and discussed, tell students that you have inside information that at the time this image was taken the sun was rather high in the eastern sky and the surface features in question are actually a series of straight and narrow trenches in the surface of the planet. Three of these trenches run East and West and are the same length. The fourth trench runs North and South and is about half the length of the others. Using this information, ask teams to model these trenches and shadow patterns using clay and light sources.