An eclipse of the sun happens when the Moon's shadow falls on the Earth. An eclipse of the moon happens when the Earth's shadow falls on the moon. Challenge each team to set up a demonstration of the relative motion of the Earth, moon, and sun that will fit their observations and can be used to demonstrate the answer to several of the questions above. At the next class session, have pairs of teams give their demonstrations to each other. Discuss differences between models.
Gravity is universal.
Bring the exercise to closure by making sure all students can explain current theory using their model. On data charts look for a complete and well organized table of observations. Note any unique observations other students do not have. On the model look for clarity of the explanation and participation of all team members.