To build a solar system mobile you will need cardboard, construction paper, an awl, scissors, string and scotch tape. On the cardboard draw a large circle. Within that circle and starting at the center, draw 9 lines for the orbits of the planets. Draw the planets and the sun on construction paper and decorate them. Cut all your drawings out. With an awl, poke one hole in each line of the cardboard and one in the center. Thread the string through the holes and attach to the cardboard with tape. Attach the sun and the other planets in order to the other ends of the string.