Learning about the planets in fourth grade is exciting, but trying to understand the solar system can be mind-boggling, too. If you are instructing a fourth grade class, you may want to make a 3-D model of the solar system as a visual aid to reinforce the things you are teaching. You can have your class make their own models at home after they see yours, to further instill the knowledge in their minds. Hang your finished model in the classroom for your students to study.
Cut a piece of cardboard into a circle about the size of a large dinner plate. Use a compass to find the center of the circle. Mark the center with a pencil.
Draw a spiral beginning at the center of the cardboard circle and ending at the outside edge of the circle.
Paint the largest ball yellow to represent the Sun. Paint the 1-inch ball orange to represent Mercury. Paint one of the 1 1/2-inch balls light yellow to represent Venus, and the other 1 1/2-inch ball blue and green to resemble Earth. Paint a 1 1/4-inch ball red to look like Mars, the 4-inch ball orange for Jupiter, the 3-inch ball yellow for Saturn, the 2 1/2-inch ball light blue for Uranus, and the 2-inch ball also light blue for Neptune. Paint the remaining 1 1/4-inch ball light brown for Pluto.
Roll out the modeling clay into a thin, snake-like strip to resemble Saturn's rings. Make a rim of glue around the ball that is meant to be Saturn. Glue the modeling clay around the ball.
Cut one 12-inch length of yarn. Cut nine 9-inch lengths of yarn.
Punch a hole in the center of the cardboard circle. Stick the 12-inch length of yarn through the hole and tie knots in the end of the yarn until it will stay put. Thumb-tack the other side of the yarn to the top of the ball representing the Sun.
Attach the planets in the same way to the cardboard circle. Hang them in a spiral in order of closest to farthest from the sun, placing Mercury closest to the Sun, then Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Cut four more pieces of yarn, each about 2 feet long. Punch four holes on the outer edges of the cardboard circle, two sets directly across from each other. Stick the pieces of yarn though the holes from the top of the circle and tie knots in the end so the yarn stays put. Gather the ends of the pieces of yarn. Tie them together. This is how you will hang your model of the solar system.