Things You'll Need
Instructions
Punch the thumbtack through one end of the string and into the center of the cardboard. Hold your pencil against the loose end of the string and pull the string taut. The pencil point should be perpendicular to the cardboard. Keeping the string taut against the pencil, move the string clockwise and draw a circle on the cardboard.
Cut 1 inch off the string. Hold your pencil against the end of the string and draw another circle. Repeat this step three more times, so you will have drawn four circles by the end of this step. These will represent the orbits of Jupiter, Saturn, Uranus and Neptune.
Cut 2 inches off the string and draw the next circle. This will leave a 2-inch gap between the four outer planets and the four inner planets. The gap is where the asteroids orbit.
Cut off 1 inch of string, hold your pencil against the end and draw another circular orbit. Repeat this step three more times. These are the orbits of Mars, Earth, Venus and Mercury.
Punch one hole somewhere along each orbit, and one hole in the center of the cardboard. This is where you will hang the planets from, so disperse the holes around the cardboard.
Use a compass to draw the diameters of eight planets and the sun. Cut the planets out of oak tag. Punch one hole along the outer edge of each planet and the sun.
Paint or color the planets and sun with marker. Decide what colors to assign the planets. When the paint dries, label the planets with black marker.
Cut nine 10-inch pieces of string. Tie one end through the holes in the planets and sun. Loop the other end through the holes in the cardboard with the orbits drawn, and tie a knot at the top of the cardboard to secure the planets. Make sure you connect the planets to the right orbit and the sun in the middle hole. From inside to outside, the order is: sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Make a hanging string for your model. Cut three 6-inch pieces of string and one 12-inch piece of string. Tape them, spread equally apart, along the outer edge of the piece of cardboard with the orbits labeled. Tie the four pieces of string together at the non-taped ends. Tie a loop at the end of the longest piece of string: this is where you will hang the 3-D solar system model.