How to Make a 3D Model of the Earth's Interior With a Foam Ball

Paint the exterior of your foam ball blue with acrylic paint. Allow the paint to dry before you continue. Apply a second coat if necessary.

Add the continents of Earth to the ball with green and white acrylic paint. Refer to a map for accuracy on the placement of the continents.

Cut out a wedge of the earth that is 1/4 the mass of the foam ball. Select a quarter of the Earth model with the least amount of land.

Draw a 1-inch wide circle on the very center of the wedge cut, drawing a semicircle on either side of the wedge. Draw another circle around the first circle an inch away from the lines. Draw the last circle an inch from the edges of the cut.

Paint the innermost circle of the wedge dark red. Paint the second circle dark orange, the third circle bright orange and the rest of the wedge yellow. Allow the paint to dry thoroughly.

Place a label on the innermost circle that reads "Inner Core." Place a label on the second smallest circle that reads "Outer Core." The third largest circle is the "Lower Mantle" and the largest circle is the "Upper Mantle."

Place one last label on the side of the foam ball, running along the outer edge of the wedge, labeled "Crust."