To shows this, a student walks around the earth telling the time and the date. Once the students have all had a chance to be part of the earth model and to grasp the concepts of time and location on the earth, the moon can be added. A point very far away is chosen to represent the sun. It is very important that the sun is not at eye level. The top of a tall tree, building, or silo far away is best chosen to be the sun.
Some preparatory exercises are again helpful.
Any students observing from outside the model will see the moon rotate one time as it revolves around the earth. The time period represented is, of course, one month. Next, the moon might repeat the revolution with the shell. At different times during the month, different phases of the moon are seen from the earth. Everyone on the earth who can see the moon at any given time sees the same phase.