Lay the foam ball on a table.
Remove chunks of the foam from the even surface using the fork, creating jagged "craters." Create several large ones and some small ones.
Mix yellow and white paint with a small dab of brown to get a light yellow color for the base color of the moon.
Paint the entire moon using the paintbrush.
Allow the moon to dry.
Mix another dab of brown paint with the remaining paint color of the moon, making it slightly darker.
Paint each of the center of the craters with the slightly darker moon color. Paint only the interior of the crater, not the surface of the moon.
Allow the moon to dry.