Please read our disclaimer. Although the annual probability of the Earth being struck by a large asteroid or comet is extremely small, the consequences of such a collision are so catastrophic that it is prudent to assess the nature of the threat and prepare to deal with it. This NASA site provides basic information about such possibilities including government reports and FAQs about impacts, asteroids and comets. Build Your Own Comet Advice and a recipe for building a six inch comet. The site also provides basic information about comets.
Students then create and observe a comet in their classroom.
Database of Terrestrial Impact Structures Natural Resources Canada provides world maps identifying crater locations. Regional maps also offer links additional information about the craters. Explore Zone EZ provides general information followed by a page with collections of news stories about the latest innovations, coolest discoveries and hottest events in world of science. A lesson for junior high students from NASA on impact craters. Topics include an explanation of impact craters, pseudocrates, and impact craters in other parts of the solar systems.