By Kim Lewis
Updated Mar 24, 2022

The solar system is composed of the Sun and eight planets. Pluto was reclassified as a dwarf planet in 2005, a decision made by the International Astronomical Union. In addition to the planets, the system contains dwarf planets, moons, asteroids, comets, and other small bodies.

Creating a three‑dimensional solar system model is a rewarding hands‑on project. By mounting Styrofoam spheres on a sheet of cardboard and hanging the assembly, you’ll have a clear, educational display that illustrates planetary positions and relative sizes.

Step 1 – Prepare the Base

Choose a cardboard sheet large enough to accommodate all eight planets. A 20‑by‑20 inch square is ideal; if you only have standard 8.5‑by‑11 sheets, tape two together to reach the required size.

Step 2 – Mark the Sun

Paint the cardboard black and allow it to dry. With a piece of chalk, draw a 3‑inch diameter circle in the center—this will be the Sun’s placeholder.

Step 3 – Define Planetary Rings

Create concentric rings around the Sun’s circle, spaced 2 inches apart. Lightly mark the intended position of each planet on these rings, using a reference diagram of the solar system for accuracy.

Step 4 – Select Styrofoam Spheres

Choose spheres that reflect planetary size ratios:

• Sun – 2.5‑inch Styrofoam ball
• Jupiter – 1.5‑inch ball
• Saturn, Uranus, Neptune – 1‑inch balls
• Earth, Mars, Venus, Mercury – 0.5‑inch balls

Step 5 – Construct Saturn’s Rings

Cut a 1.5‑inch Styrofoam disk and remove a central portion to create a ring. Glue this ring onto the center of a 1‑inch Styrofoam sphere to represent Saturn’s iconic rings.

Step 6 – Paint the Planets

Use the following color scheme to bring realism to the model:

• Sun & Venus – yellow
• Mercury – orange
• Mars – red
• Earth – green and blue
• Uranus – green and dark blue
• Neptune – sky blue
• Jupiter – yellow with brown patches
• Saturn – brown body with a yellow ring

Step 7 – Attach the Spheres

There are two reliable methods:

• Drill small holes in the cardboard, slide each sphere through, and secure with a dab of glue.
• Halve each sphere and glue one half onto the cardboard, ensuring the ring on Saturn aligns correctly.

Re‑paint any areas where glue may have smudged the colors.

Step 8 – Hang the Model

Cut two holes on opposite sides of the cardboard, thread a length of string through both, and hang the completed model from a hook. This display can serve as a striking educational prop for classrooms or home learning.

Materials Needed

• Solar system diagram (for reference)
• Cardboard sheets
• Pencil and chalk
• Scissors or utility knife
• String
• Glue (clear or white)
• Tape
• Paint and paintbrushes

TL;DR

Use small white paint dots to mimic moons and other celestial bodies. To draw circles without a protractor, tie a string to a chalk piece, hold the other end, and trace a perfect circle.