Created by two NASA scientists and selected as one of the Exploratorium in San Franciso's "Ten Cool Sites", the Exploration of Earth's Magnetosphere is a great learning site. Before diving into detailed descriptions of "the Earth's environment in space," readers can learn about the history of the site as well as the history of research about the magnetosphere. The Overview also provides a glossary for those not familiar with space terminology and those needing a refresher. Thirty-five chapters explain the magnetosphere, discussing every detail from electrons to auroral acceleration in a manner that does not require extensive mathematical knowledge. Teachers will be interested in the Classroom Resource, which suggests ways to use this site as a learning tool.