Middle school students can make delicious potatoes that look like asteroids. First, have students look at several pictures of asteroids so they get a firm idea of what asteroids look like. Then make up a large batch of instant mashed potatoes. You want to make them a little thicker than normal, so the students can mold the potatoes. Give each of the students a pile of mashed potatoes to work with. Students should mold the mash potatoes into uneven oval and oblong shapes that look like the asteroids in pictures. Students can use their fingers to created holes and craters in the potatoes; then, the asteroid-potatoes should be put back in the oven and baked for approximately 20 to 25 minutes at 375 degrees Fahrenheit.
The largest asteroid belt is located between Mars and Jupiter, and it creates a full ring within the solar system. Even so, most solar system models only show the sun and the planets. Have students make a model solar system that includes the asteroid belt. To do this, the solar system can be created on a large piece of cardboard. Foam balls can be cut in half and used as the planets. Students can use either small stones or pebbles as the asteroids. Each of the planets should be painted so they can be identified visually, and the cardboard background can be painted dark to look like outer space.
Asteroids are uneven in shape and density. Their appearance seems to change when being looked at from Earth because of shadows. To demonstrate this, have students crumble up pieces of brown or black construction paper. Attach the crumbled pieces of paper to a string using a clip or stapler and then hold the other end of the string up in front of a wall so the paper is dangling. Finally, have a student hold a flashlight facing the crumbled piece of construction paper. The shadow cast on the wall represents what astronomers can see of asteroids from Earth. The black construction paper will cast a darker shadow and represent asteroids made mostly of stone. The brown paper will cast a lighter shadow and represent asteroids made mostly of carbon.
This activity is designed to give students an idea of the actual size of an asteroid. You will need several maps of the United States and the dimensions of several known asteroids. Pictures of those asteroids would also be helpful for the demonstration. Have students take the dimensions of the asteroids and figure out the size of those asteroids when compared to areas of the United States. For example, the largest known asteroid is larger than the state of Texas. Having the students actually draw out the approximate size of an asteroid on a map of the United States will give them an understandable point of comparison.