How to Create a Solar System Model to Scale with Your Kids

Learn to build an accurate, proportional solar system model that helps children understand the vast distances and sizes in space.

1. Choose Your Scale and Space. First, decide what scale works for your space. If you make the Sun the size of a basketball (about 9 inches), Earth would be the size of a peppercorn and sit about 100 feet away. For most homes, try making the Sun a marble (half-inch) — then Earth becomes a grain of sand 10 feet away. You'll need a long hallway, backyard, or local park for the outer planets. Write down your scale so you can calculate each planet's size and distance.
2. Gather Your Materials. You'll need objects of different sizes to represent planets. For a marble-sized Sun, gather: a grain of sand (Earth), a slightly smaller grain (Venus), a tiny speck (Mercury and Mars), a small pea (Jupiter), a slightly smaller bead (Saturn), and two pinheads (Uranus and Neptune). You'll also need a measuring tape, sticky notes for labels, and a long string or rope to mark distances. Consider using different colored objects or painting them to match each planet's appearance.
3. Calculate Planet Sizes. Use simple ratios to size your planets. If your Sun is 0.5 inches, then Jupiter should be about 0.05 inches, Earth about 0.005 inches, and so on. Don't worry about being perfectly precise — the goal is showing relative sizes. Many planets will be practically invisible, which is actually the point! This helps kids understand how tiny Earth really is compared to the Sun and how much empty space exists in our solar system.
4. Mark the Distances. This is where it gets really interesting. Using your scale, measure out where each planet belongs. For a marble Sun, Mercury sits about 2 feet away, Venus at 4 feet, Earth at 5 feet, Mars at 8 feet, Jupiter at 28 feet, Saturn at 52 feet, Uranus at 104 feet, and Neptune at 163 feet. Use your measuring tape and place sticky note labels at each spot. If you don't have enough space, you can fold the model or just do the inner planets.
5. Set Up Your Model. Place your Sun object at one end of your space. Walk to each measured distance and place the corresponding planet object with its label. If working indoors, you might snake through different rooms. Take photos at each planet to document the journey. Have your kids walk the distances between planets to really feel the vast emptiness of space. Time how long it takes to walk from Earth to Jupiter — this helps make the scale tangible.
6. Explore and Discuss. Once your model is complete, explore it together. Ask your kids what surprises them most. Walk from planet to planet and talk about what they notice. Discuss how long it would take a spacecraft to travel these distances, why we can see some planets from Earth but not others, and how this changes their understanding of our solar system. Take photos of your family standing next to different planets to show the scale.