Easy and inexpensive solar system project examples include using foam or balloons to represent the sun and the eight planets that revolve around it. Other solar system projects for kids include making planets out of candy or scaling up the project using strategically placed rocks in the yard.
To build a three-dimensional solar system model, use different colored balloons to represent the various celestial bodies. For example, use a yellow balloon for the sun and a red one for Mars. Inflate the balloons to different sizes depending on the planet each one represents, and use a piece of yarn to hang them in line starting from the sun to the last planet.
A hanging solar system foam model involves representing the eight planets and the sun using different-sized Styrofoam balls bought from an arts-and-crafts supply store. With the largest ball representing the sun, assign planet names to the rest of the Styrofoam balls depending on their relative size. Use nontoxic paint, finger paint or markers to paint the balls in planet-themed colors, and then use dowel rods to connect the planets to the sun at the center.
For a candy model, cut out a piece of cardboard from the side of a big appliance box, and use it as the base of the project. Draw a dot at its center, and then draw concentric circles around it. Use different candies to represent the different planets, and glue them on their respective orbits with the sun in the middle.