ACTIVITY: The Scale of the Solar System

In this activity, you'll investigate the concepts of relative size and distance by creating a basic model of our solar system.

Materials: Nine dowel rods, 9 index cards, permanent maker, meter stick having cm and mm marked, scissors, calculator, colored yarn, string or ribbon.

Teacher Demonstration: Use a Styrofoam ball and a knitting needle to represent the Earth, a flashlight represents the Sun. Push the needle through the ball and shine the light on the "Earth". Ask the students which side is night and which is day. Turn the ball while you discuss a 24-hour day (rotation). The Earth is rotating, what would happen if the Earth did not rotate? Use a clock and the demonstration to show students the relationship of time to the movement of the Earth.

What to do: Using this size/distance scale table shows how large each planet is and how far it is from the Sun. Mount an appropriately sized object for each planet on an index card and glue it to a dowel rod. For example, the Sun can be a small styrofoam ball, Jupiter and Saturn are small ball bearings, and Earth and the smaller planets are grains of sand. It is not necessary to have each object (particularly the small ones) precisely the correct size; choose available materials that are reasonably close to the specifi ed sizes. Label each card with the planet's name.

If the Sun were the size of an orange: Mercury=hole made by a staple; Venus=thickness of a small paper clip; Earth=thickness of a paper clip; Mars=1/2 the thickness of a paper clip; Jupiter=thickness of a pencil, be generous; Saturn=thickness of a pencil; Uranus=size of the eyelet of a tennis shoe; Neptune=size of the eyelet of a tennis shoe; Pluto=thickness of a small staple.

Choose a point in the center of a large room, or outdoor space, as the Sun and mark it as your starting point. Place each planet around the Sun. Begin with Earth as the starting point, 1.5 meters from the Sun. Have the students put the dowel rod in the ground and stretch a colored ribbon, yarn or string from the Sun to the Earth. Repeat this for each planet making sure they are in the correct order around the Sun.