One of the trickiest, yet most important, Astronomy concepts for children to understand is the Earth-Moon-Sun relationship. The idea of rotation and revolution, while extremely basic, is the foundation of understanding motion in our solar system. These three objects have the greatest impact on our lives– the Moon orbits the Earth and the Earth orbits the Sun. The Earth rotates on its axis (once every 24 hours) and causes the Sun to rise in the east and set in the west. The moon orbits the Earth (once every 29 days, in respect to the Sun), causing lunar phases.
Having children construct a model is one of the best ways to help them understand these motions. You can purchase the activity here and have your child assemble the model below– you only need paper, scissors, and two brass paper fasteners.
You can also have them act out these motions. Tell your child that you will be the Sun, she will be the Earth, and have her hold a ball (representing the moon). Then ask her to orbit around you, representing a year. Then she can add in the orbit of the moon around her (the Earth). Once she has these two motions down, she can combine them. You can ask her to try and fit 12 full revolutions of the moon around her, while orbiting the Sun only once– it gets a little tricky!
There are many ways to help your child understand the Earth-Moon-Sun relationship. Once they have the basics of rotation and revolution down, they are ready for season and lunar phases!