Created and developed by Laura Jean Checki
To explore the different parts of a comet, to learn how and why the tails of a comet form and what a comet looks like when it is far from the Sun in its orbital path, to understand how cosmic objects are named.
White Model Magic, pebbles, soil, bright blue shiny ribbon, opalescent ribbon (pale blue or white), white ribbon with silver sparkles inside, spoons, scissors, comet certificates, individual bags.
Distribute to each student: a baseball or golf ball sized portion of model magic; 1 pebble, 1/2 teaspoon of soil, 1 piece of bright blue shiny ribbon approximately 24″ long, 3 or 4 pieces of the opalescent and white sparkled ribbon.
The sphere represents the coma, the pebble the nucleus, the bright blue shiny ribbon the ion tail and the additional ribbons represent the gas and dust tail.
Have the students roll the model magic into a spherical shape. Once the model magic is warm and malleable have the students make an indentation in the model magic and insert the soil. Have them roll the model magic so that the soil spreads throughout the sphere. Once the soil is well distributed have the students take a pebble and insert the pebble into the center of their sphere with their finger. They can then roll or pinch the model magic to close the pebble inside. At this point you can instruct them to insert the ribbon in the same fashion that they inserted the pebble. If mobility and dexterity are issues you can tape the ribbons or tie them together so that the student need only insert the ribbons once. Some students like to have their ribbons curled lightly with scissors. The comet is complete at this point and, when thrown, easily demonstrates the effects that the Sun and solar wind have upon these objects.
I always begin this activity with a detailed explanation of comets and their parts so that the students understand what they are creating. I also hand out NASA’s Cool Curious Comet fact sheet. In addition, if time allows, I like to create certificates and have them name their comets with a “real” designation such as the initials of their school with the date and a letter: (RS5212011A) and a common name such as comet Halley. This opens up the discussion about how we name celestial objects. Finally, I like to have the students write their names on lunch bags and place their comets and certificates inside of the bags so that they can be picked up at the end of the school day and not carried around or thrown at each other in the hallways during school hours.