Many earth science courses include an introduction to the solar system. The challenge of earth science is to understand the natural processes that shape not only our planet, Earth, but all objects in the solar system. But there are more compelling arguments for including planetary science in the classroom. Those arguments, some of which are outlined below, inspired NASA to conduct short courses in planetology for earth science teachers at the secondary and college levels. This book is an outgrowth of these short courses. Science education is an integral part of scientific endeavors. When the National Aeronautics and Space Administration was created by an act of Congress in 1958, its charter required the agency to "provide for the widest practicable and appropriate dissemination of information concerning its activities and the results thereof." Part of that responsibility includes introducing students to the scientific results of planetary exploration. This volume is designed to help meet this goal. The activities are written either to supplement or to introduce topics usually encountered in earth science courses. Consistent with the rationale outlined above, most activities deal with new concepts in planetary geology, but, when generalized to include terrestrial processes, can illustrate broad problems in the earth sciences. The exercises are not keyed to any particular text; rather, each addresses concepts as independent units. The exercises are grouped into five units: 1) introduction to geologic processes, 2) impact cratering activities, 3) planetary atmospheres, 4) planetary surfaces, and 5) geologic mapping. Although each exercise is intended to "stand alone," students will benefit from having worked some of the prior exercises. For example, it would be difficult for students to work exercises in planetary geologic mapping without some knowledge of geologic processes and planetary surfaces. The suggested introductory exercises are noted at the beginning of each exercise. Depending on the level of the student and the context of the exercise, the sequence of the units is somewhat cumulative. Depending on the instructor, activities can be adapted to most levels of instruction by modifying the questions and adjusting the expectations for answers. A list of suggested correlations of activities with topics commonly covered in earth science courses is included for the convenience of the instructor.