The activities in this guide deal with concepts in planetary geology, but they can be generalized to illustrate broad problems in the earth sciences. They are designed to supplement or introduce topics usually encountered in earth science courses. The exercises, organized into independent units which can be presented in any order, are appropriate for secondary and postsecondary education; however, most can be adapted to the elementary level as well. Each activity is printed twice: once in a form suitable for classroom use with objectives, materials needed, background information, procedures, and questions; and again with answers and suggestions for the teacher inserted in the appropriate blanks. The following units and activities are included: (1) lunar phases (understanding phases of the moon); (2) planetary cratering (impact cratering and comparing cratering processes); (3) Aeolian processes (Martian wind tunnel); (4) planetary atmospheres (Coriolis effect and storm systems); and (5) geological mapping of other planets (photogeologic mapping of the moon, planets in stereo, landform mapping, and geologic features of Mars). Appendices provide information for ordering National Aeronautics and Space Administration (NASA) motion pictures and publications, sources of space photographs, suggestions for correlating topics of the activities, and a glossary of planetary geology vocabulary. (DC)