Coloring Activities
For a simple, low-maintenance, yet enjoyable activity for the pre-K classroom, set aside time for children to color pictures of the planets. Print out outlines of the planets and provide children with markers, crayons and colored pencils. Use pictures that contain lots of small lines for children to color between to develop fine motor skills. Provide children with colored pictures to look at for reference, or have them color the pictures after reading about the planets -- and their colors -- together as a class to encourage memory retention.
Planet Mobiles
Simple planet mobiles are easy and enjoyable for preschool-aged children to assemble, while encouraging fine motor skills. Print out two identical pictures of each of the nine planets in the solar system per mobile, and cut them out. Planets should range in size from 2 to 10 inches in diameter, with the gas giants such as Saturn and Jupiter larger than small, rocky planets such as Mercury. Trace a thin line around each planet picture onto colored card stock, cardboard or heavy construction paper about 1/2-inch out from the edge of the planet picture, forming a border. Cut the shapes out and glue the same planet picture onto both sides of the corresponding shape. Cut a 10-inch circle from card stock or cardboard. Punch a hole through all the planets and tie varying lengths of clear fishing line through each hole. Make 10 small holes in the circle and thread each line through a hole, tying at the top. Use the center hole to string a piece of line through for hanging in the classroom or child's bedroom. Have children embellish the planet pictures with glitter, foil, craft crystals, markers or glow-in-the-dark paints, and allow them to help with stringing the planets up through the mobile circle top.
Dioramas
Kids of all ages will enjoy making a space diorama that represents the planets in the solar system, even at the preschool level. Have children paint the insides of shoe boxes black with non-toxic poster paint, and assist them in using glue and glitter to make star clusters in the background. Use small Styrofoam balls, paint and invisible fishing line to make and hang planets from the top of the box. Or cut out pictures of the planets and tape those inside the box for a quicker project with less mess.
Other Activities
Children learn not only through hands-on activities, but kinesthetic, audio and visual activities as well. Make up or print out the words to a planet-related song and teach it to children, allowing them to play instruments as they sing the song. Listen to slow, atmospheric music and encourage children to walk very slowly, as though they were on one of the planet's gravity-free moons. To represent the sizes and distance between planets, gather nine balls ranging in size from gold balls to big bouncy or exercise balls, and have children place them around the classroom floor in accordance with picture books and other references that demonstrate the planets' sizes and locations in the solar system.