Making a 3-D model of the solar system is a great way to have fun with students while giving them a unique educational experience. Make a 3D model of the solar system in several hours using foam balls of different sizes, tempera paint, small paint brushes and thin dowel rods.
Paint the smaller planets
Use 2-inch balls for Earth and Venus, a 1 1/2-inch ball for Mars and a 1-inch ball for Mercury. Using blue and green paint, draw patterns of oceans and land on Earth. Use yellow paint for Venus and red paint for Mars. Cover Mercury using a reddish-orange paint mix. Allow the planets to dry for at least an hour.
Paint the larger planets
Use 4-inch balls for Uranus and Neptune, a 6-inch ball for Saturn and a 7-inch ball for Jupiter. Paint Neptune blue, Uranus green and Saturn yellow with a red ring. Color Jupiter reddish-brown with a big red spot.
Paint the sun
Use a 10-inch or larger ball for the sun. Paint it yellow, and allow it to dry.
Assemble the solar system
When the paint is dry to the touch, place eight dowel rods of varying lengths into the ball that represents the sun. The rods should stick out horizontally and face different directions. Place the planet Mercury on the end of the shortest rod, Venus on the next shortest and Earth on the next one. Place Mars after Earth, followed by Jupiter and then Saturn. Finally, place Uranus on the second-longest rod and Neptune on the longest one.