Principle
The earth performs two main rotational motions. On the one hand, it rotates around itself, and on the other hand, it orbits the sun. However, it does not follow a perfect gyroscopic motion. For one thing, the Earth's axis of rotation is tilted. This tilt is responsible for our seasons. For another, the Earth does not move in a perfect circular orbit around the Sun, but in an ellipse. As a result, the Earth is slightly closer to the Sun in January than in July
Students will use the Sun-Earth-Moon model to derive the Earth's sense of rotation. They also use the model to understand the tilt of the Earth's axis and the elliptical shape of the Earth's orbit.