According to Dennis Schatz of the Pacific Science Center, there is no better way to get students to understand the nucleus of a comet than to have them build their own miniature model comet.
To build the comet with students you will need a bucket, plastic wrap, 2 cups of water, 2 spoonfuls of charcoal, a dash of ammonia, a drop of any type of organic material, a pinch of salt, a pinch of sand, and 2 cups of dry ice.
First, combine all ingredients except the dry ice in a bucket. Second, mix the ingredients with a wooden utensil. Third, add the dry ice and stir until the mixture is stiff. Fourth, lift the plastic wrap out of the bucket by the corners and mold the mixture inside into a ball through the plastic. Finally, place the formed mixture on the table and observe.
The model approximates the physical constitution of comet nuclei and will impress upon students the various constituent parts of a comet.
This simple activity, suggested by the University of Washington's astronomy department, will quickly and effectively teach students about the expansion of the universe.
Have five students stand shoulder to shoulder at the front of the classroom facing the class. Next, ask every student in line to simultaneously move apart and spread their arms, so that their arms are fully extended and their fingers are barely touching. Have the class notice that from the perspective of the student in the middle of the line, each of the other students has moved away at a different speed. The people directly to the right and left of the middle person have moved 2 arm lengths away in about 2 seconds, but the people near the end of the line have moved several arm lengths away from the middle person in the same amount of time. In other words, more distant objects moved away at a faster rate than closer objects. Have the students discuss how this same principle applies to the expanding universe.
This activity, suggested by the Montana State University astronomy department, will help students learn about lunar cycles.
Have students observe the moon every night for at least eight weeks. Have students keep a log of sketches and observations that chart the changes in the moon's appearance and position. After the first four weeks ask students to predict the moon's position and appearance based on past observations, and hold discussions regarding the different phases of the lunar cycle. Finally, create a lunar calendar that accurately describes and predicts the lunar cycle.
This activity, suggested by Berkeley University's astronomy department, is an easy way to teach students how to calculate the size of interstellar objects.
First, make a pinhole. To do this, cut a small square hole 3 centimeters across in a piece of cardboard. Next tape a piece of aluminum foil across the square hole and poke a tiny hole in the foil using a needle.
Second, expose the pinhole to sunlight to project an image of the sun on a piece of paper. Use a ruler to measure the diameter of the projected image.
Finally, show that since the ratio (diameter of the sun) / (distance from sun to earth) is equal to the ratio (diameter of image of the sun) / (distance from pinhole to image), one can find the diameter of the sun by dividing the diameter of the image of the sun by the distance from the pinhole to the image and multiplying that value by the distance from the sun to the earth.