An ice cream and candy comet makes a "cool" end to a hot day while demonstrating a comet's internal structure. Prepare the comet nucleus the day before by mixing vanilla ice cream with chopped candy bars, nuts and caramel. Give each student a bowl and put one round scoop of the ice cream and candy mixture into it. Place in the freezer overnight. The next day, give students a cup of ginger ale each and have them pour it over the ice cream. The carbon dioxide in the carbonation will cause a foamy coma to form around the ice cream nucleus. Spray two long lines of whipped topping out one side for the tails. Discuss what each component in the treat represents in a comet and then enjoy the feast.
Entertain your students with a game of comet darts that will have comets flying right in your classroom. Tape or tack some long pieces of red, yellow and orange ribbon to several Styrofoam balls covered with tin foil. Stick several Velcro adhesive dots to each sphere. Cut a large square of black felt and a sun of yellow felt. Glue the sun in the center of the square. Draw three to five concentric orbital circles around the sun with white or silver puffy paint. Assign point values to each ring. After the paint dries, hang up the dart board and take turns hurtling the comets toward the sun with tails flying high. The person with the highest point value for her toss wins the round.
Building a model comet illustrates the internal components and demonstrates how the tail forms. Wear goggles and protective gloves. Crush 5 lbs. of dry ice to a snow-like texture. Mix 2 1/2 cups water, 1/2 cup of sand, 1 tbsp. ammonia and a can of cola in a metal bowl. Stir in 2 1/2 cups dry ice until vapor forms and the mixture gets slushy and thickens. Pack the slush into a ball and spread a layer of sand over the surface. Pour water over the dry ice ball to form another layer of ice. Blow hot air on the comet with a hair dryer and watch the tail form.
Beginning with Sir Edmund Halley's discovery of Halley's Comet in 1705, scientists have been observing and learning about the many comets that pass through the solar system every year. NASA launched the Stardust mission in 1999 and the Deep Impact mission in 2005 to study comets up close. Famous comets include Hale-Bopp, Halley, West, Shoemaker-Levy 9, Tempel-Tuttle, Encke and Wild 2. Students can research the NASA missions, the history and beliefs about comet sightings in ancient times and choose one famous comet to learn about in detail. Presentation methods for compiling and sharing the research include a digital slide show, an oral report, a skit or puppet show or a traditional written school report.