A tellurium is a model that can be used to represent the movements of the earth and the moon around the sun. This tellurium is not a true representation of reality, but a model to explain the various phenomena such as day and night, summer and winter and the phases of the moon. The relationship between the different elements differs greatly from the real dimensions in our solar system. There are three important rotary movements in our sun-earth-moon system: - The earth rotates about its axis every day. This is the cause of day and night and of seeing the sun, moon and stars go by in the sky. - The moon turns around the earth in about four weeks. The four phases of the moon can be attributed to this. - The earth orbits (along with the moon) the sun in one year. This results in four seasons, in which different constellations can be seen in the night sky. By rotating the globe and illuminating it with a flashlight, the rhythm of day and night is explained. When the doll is glued to the equator with an adhesive pad, it can be seen that the shadow of the doll is shortest at 12 noon and is low in the sky at the beginning and end of the day when the sun is viewed from the doll, the longest. It also becomes clear that the sun rises in the east and sets in the west.