A flat world map is no comparison for a physical model of the Earth. Styrofoam balls are often used in school projects to allow children to create their own Earth models. These crafts provide ways to model both the exterior and the internal composition of planet Earth. There is nothing like having the world at your fingertips to spark an interest in other civilisations, the solar system or world geography.
Painting the Earth's continents and oceans directly on the styrofoam ball can be a bit challenging. To hold the ball still while painting, it is helpful to hammer a nail through a small block of wood to create a stand for the ball. Also, the porous surface absorbs a lot of paint, so multiple coats are needed. Use a marker to create a dotted line marking the outline of the continents, then fill the outline with green tempera paint and the oceans with blue tempera paint.
Since it can be difficult to evenly paint the surface of styrofoam, paper mache can be used to coat the outside of the ball before painting it. Use short, thin strips of white paper so that the paper mache provides a smooth white surface for painting the continents and oceans. You may wish to hold the ball steady for the paper mache and painting processes by placing it on the tip of nail poking through a wooden base.
Layers of the Earth
For added educational value, cut away a quarter of the styrofoam ball prior to any painting. Use this missing section to provide a view of the inside of the Earth. Use a marker to create a dotted line marking the layers of the Earth. Fill inside the marked lines with a brush and tempera paints. Paint the exterior of the Earth to show continents and oceans. You may wish to hold the ball steady during painting by placing it on the tip of a nail poking through a wooden base.
Save and display your styrofoam Earth by making it a globe. Use an ice pick to core out the centre of the styrofoam Earth. Straighten a metal hanger to create a rod for the centre of the globe. Cut the hanger to size, leaving enough to fold down to make a smooth end on the top and enough to glue to a wooden base at the bottom.