Earth's orbit

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.