Asteroids are classified based on color and brightness, also known collectively as spectra. Spectra measurements are called albedo and refer to the amount of light reflected. This is measured from zero, which equates uniformly black and one which means perfect reflection. Scientists classify asteroids based on where they fall in this measurement. Spectral classifications include carbonaceous, silicaceous, and metallic types. Carbonaceous asteroids measure from .03 to .09 albedos and are the darkest variation and account for over 75 percent of all asteroids. Silicaceous asteroids, equaling 17 percent of asteroids in the asteroid belt, measure .10 to .22 albedos. Metallic asteroids are primarily made of metallic iron and are moderately bright with an albedos range of .10 to .18. Students can demonstrate the different types of asteroids through a series of models and visual aids to explain the spectral classification system. Models for the project can be created using painted rocks or clay sculptures in the shape of asteroids.
Orbiting between Jupiter and Mars, the asteroid belt is the unformed materials for a planet. However, the large amounts of gravity on Jupiter are thought to have stopped the process creating a belt of 100,000 asteroids. Designing a model of the asteroid belt for a science fair project, students depict the two separate belts that create the phenomenon. The first is the main asteroid belt, and the second are Trojan asteroids, which exist on the outside of the overall structure and maintain a stable orbit. Students can also highlight specific asteroids, such as the Ceres asteroid, which is equal to 30 percent of the total asteroid belt. Models are created using painted foam shapes mounted on two wire rings.
While asteroids are believed to be unformed planetary material, comets are the material that is left over after the Solar System formed. Comets travel in an elliptical orbit that passes by Earth. As comets come closer to the Sun they develop their distinct tails due to solar wind. Comet tail debris, termed meteoroids are what create meteor showers. When meteorites fall through the Earth’s atmosphere, surviving both journey and impact, they become known as meteors. Projects chronicling or modeling the transformation from comet to meteorite illustrate the interrelation of different celestial phenomenon. Students can demonstrate this process through rock or clay models as well as through visual and informational displays.
Once the stuff of science fiction, mining precious metals and minerals from comets and asteroids has become an increasingly possible solution to natural resource deterioration on Earth. The low gravity of asteroids and comets make them ideal targets for the mining of the future. Not only are they rich in materials, but would be more economical to mine. Theorizing on the possible future of asteroid and comet mining, science projects can build models of the process of mining with additional charts to illustrate the profitability of such endeavors. For example, charts can be used to show the expected mineral content of an average asteroid or comet as compared to mining output on Earth.