Painting Styrofoam Balls as Planets

Use a water-based craft paint such as acrylic paint on the Styrofoam. Read the label to make sure the paint is OK for Styrofoam. Some paint, such as spray paint, will simply melt the foam.

Use different sizes of Styrofoam to represent the different sizes of the planets. The sun needs to be the biggest Styrofoam ball. Jupiter needs to be represented with the next size down, with Saturn following behind. Neptune and Uranus should be a size down from Saturn. Earth and Mars should be about half the size of Uranus and Neptune. Mercury and Venus should be represented with the smallest size Styrofoam balls, about half the size of Earth and Mars. Don't include Pluto, as it was redefined as a dwarf planet in 2006.

Cover each planet in its own distinctive color with a craft foam brush. Go over the ball with one coat. Place a toothpick into the planet and place the opposite end of the toothpick into a separate piece of Styrofoam. This will let the entire circumference of the planet dry.

Paint the sun yellow. Use a brownish-red color for Mercury, yellowish-brown for Venus, blue with white streaks to represent Earth, a deep red for Mars, brown with white streaks to represent Jupiter, bluish-green with white streaks for Saturn, a turquoise blue for Uranus, and deeper blue for Neptune. Paint the Styrofoam ring to go around Saturn in the same manner as the planet itself.

Apply a second coat over each planet and let the planets dry before displaying them.