Make a Sun, Moon and Earth model

DIY ASTRONOMY | Practical astronomy projects for every level of expertise | A simple, hands-on project to teach their surface features and orbits to beginners and youngsters

- Mary McIntyre

The concept of lunar and planetary orbits can be difficult for beginners to grasp. This simple flat model will help you to introduce these ideas by showing that the Moon is in orbit around Earth, but the Earth-Moon system is also orbiting the Sun. The model is easy to make using just one sheet of A4 card, some paper fasteners and a dash of artistic flare.

Although Earth and the Moon in our model are the correct sizes relative to each other, it goes without saying that the size of the Sun and the distances between the bodies are not to scale. If they were, our Sun would have a diameter of 10.9 metres, the distance between Earth and the Moon would be 2.76 metres and the distance between the Sun and Earth would be 1.2km. If the Sun and Earth were the correct sizes relative to the distance in our model, the Sun would have a diameter of approximately 2mm and the Earth a diameter of approximately 0.018mm. The surprising size of these numbers is a great teaching opportunity, conveying the fact that space is big! Models and diagrams commonly used to show our Solar System are never to scale because the relative sizes and distances are far too large.

There are several more learning outcomes from creating this project. When drawing Earth, there is much to learn about the geography of our home planet - not just the shapes of the continents, but also why some areas are very green and lush while others are brown and arid. There are many photographs of Earth as seen from space online, so choose one that shows the continent where you live.