ProtoStars: Planetarium show for Children K-2
Pre-Show Activity 1
Bringing the Solar System to Life

Objectives:
• Students make models which do NOT represent relative sizes of planets.
• Studens use their models to show revolution and rotation of the planets around the Sun.
• Students learn about 'revolution', 'rotation', and 'orbit'.
2-3
Materials
• One yellow punch ball
• Nine balloons of different colors
• Chalk or string to mark orbits
• Resource materials to check orbits of the nine planets.
Procedure
• Children blow up the yellow punch ball and the balloons. Explain that if they wanted to represent the planets on the same scale as the punch ball, they'd have to use grains of sand, and small beads, which would get lost! So we just pretend that the planets are MUCH bigger compared to the Sun than they really are.
• Take the class outside or go into the gym inside. Have nine paths marked on ground or floor with string or chalk.
• Have one student hold each balloon. Another student will hold the yellow punch ball which represents the sun.
• Have one student hold each balloon. Another student will hold the yellow punch ball which represents the sun.
• The "sun" stands in the middle of a circle. The other children take their places on the marked paths. Teacher will need to give each child the name of his/her planet and direct him/her to the correct place.
• Begin the experiment by having children walk in their path or "orbit" around the sun. Stress that the planets never leave their own orbits. This travel around the sun is called "revolution". This term should now be introduced.
• After the children have orbited the sun once, bring in the added concept of "rotation". While moving around the sun, the children should also start to spin around like tops. (Caution them against becoming dizzy.) This demonstrates "rotation". Tell children that it takes one year for the earth to revolve around the sun, and it takes one day for the earth to rotate on its own axis.
• Point out that "rotation" or spinning on one's own axis takes much less time than going all the way around the sun, "revolution."
• Give all children in the class a chance to try the experiment.