This teacher website provides a comprehensive lesson unit on the structure of Earth's atmosphere and how it sustains and impacts life on Earth and its ecosystems. Includes labeled diagrams, student worksheets, a slideshow, flashcards,...

Excellent Eight Planets site that provides a vast amount of information about planet Earth. Very comprehensive and complete site.

Apple provides a description of the USAtlas Geology app, developed by the USGS. The app provides 46 layers of vector information available at The National Atlas of the United States Website.