This is the rotation of the earth around the sun. Relate this to your age and also to the idea of a leap year. The seasons observed in North East Indiana can be accounted for using the two earth's motion and two other factors. Introduction to the great circles and small circles. Great circles are circles that divide the world into two equal halves such as all line of longitude, whereas, small are circles that do not divide the world in two equal parts.
All lines of latitude are small with the exception of the equator.
Certain small circles are of importance when one considers the season. These lines or circles are important when discussing the seasons here in Indiana. The seasons are different from place to place. Four reasons we can use to explain the four seasons. Use diagrams, drawings, models or slides to illustrate this concept of change in seasons.