A DIY solar system model can teach planet order, relative size or distance, but a small tabletop display usually cannot show all three accurately at the same scale. Decide what your model is intended to explain before choosing materials. This project offers two complementary versions: a labelled display for identifying planets and a distance model that reveals how much space lies between them.
DIY Solar System Model: Choose What Is to Scale
Our solar system includes the Sun and eight planets, along with many other bodies. For this introductory model, use Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Explain that leaving out moons, dwarf planets and smaller bodies makes the model simpler, not complete.
NASA JPL’s scale-model project distinguishes modelling planet sizes, distances or both. Its Solar System Scroll activity also addresses the misleading impression that planets are evenly spaced. Use these resources to check your chosen scale and learning goal.
Version One: A Labelled Tabletop Display
Materials: card, paper circles or suitable craft balls, colouring materials, glue appropriate for the children present and paper labels. Use large pieces where small objects would be a choking risk. An adult should handle difficult cutting. Avoid sharp skewers and hot glue in a beginner activity.
- Make a large label for the Sun and one label for each planet.
- Choose clearly distinguishable shapes or colours, using NASA references rather than assuming every artistic colour is a literal view.
- Place the planets in order from the Sun.
- Add a visible note: “Planet sizes and distances are not shown to the same scale.”
- Ask the child to explain what the display shows accurately and what it simplifies.
Jupiter should be represented as larger than Earth if you are illustrating relative size informally, but do not call the display an exact size model unless you calculate and measure the dimensions. Attractive spacing is not evidence of accurate distance.
Version Two: A Distance Model
For an illustrative outdoor model, use a scale of one metre representing roughly one hundred million kilometres. The rounded distances below are measured from the Sun, not from the preceding planet. They represent approximate orbital distances, not fixed positions of planets that remain in a straight line.
| Planet | Approximate model distance from the Sun |
|---|---|
| Mercury | 0.58 m |
| Venus | 1.08 m |
| Earth | 1.50 m |
| Mars | 2.28 m |
| Jupiter | 7.79 m |
| Saturn | 14.34 m |
| Uranus | 28.71 m |
| Neptune | 44.95 m |
Check the values and scale with the NASA resource before using them for a formal school assignment. The rounded figures are sufficient to discuss spacing, not to predict where a planet is today.
Set Up the Distance Walk Safely
Choose an approved level area away from traffic, water hazards and restricted spaces. An adult should assess weather, access and supervision. Never look directly at the Sun during an astronomy activity. Use a labelled card on the ground as the model Sun.
Measure every position from that starting point and place a large planet label at each distance. Keep labels clear of walkways and avoid string stretched where people could trip. If you do not have approximately forty-five metres of safe space, choose a smaller scale or use a paper-strip activity.
Ask children to predict where the outer planets will go before measuring. Compare their predictions with the model and discuss why many familiar illustrations compress the empty space.
Why the Planets Become Tiny at This Scale
At the distance scale above, Earth’s diameter would be about 0.13 millimetres and the Sun’s about 14 millimetres. Large craft balls placed along the walk therefore represent location markers, not correctly scaled planet sizes. State that explicitly.
This is the central learning point: a model can make one relationship easier to see while distorting another. A tabletop display and a distance walk can both be useful when their limitations are labelled honestly.
Questions for Different Learners
For younger learners: ask which planet comes next, which group lies closer together and which gaps surprised them. Let them draw or dictate an observation.
For older learners: ask how the positions change if one metre represents twice as much real distance. All model distances halve. Ask why doubling the size of only Earth would break a consistent scale.
Another extension is to compare a distance model with a size-only model. Keep the two labelled separately so a learner does not mistake the combined display for one consistent physical representation.
Keep the measurement record with the finished display. If another group rebuilds it using your instructions, they should know the starting point, the unit and the rounding used. Clear documentation makes the model easier to check and improve.
Finish with a Model Explanation
Ask the child to complete three sentences: “Our model shows ___ accurately. It simplifies ___. We chose this scale because ___.” That explanation is more valuable than a perfectly painted set of balls with no account of scale.
Explore our Science hub for further explanations and our STEM projects hub for practical investigations.
