I'm a space radiation physicist taking a planetary geology course for professional development, and I picked up the 4th Edition (1999) of this book as a supplementary reference for the course. I ended up reading it cover-to-cover, making notes and learning a ton of new material. This text is light on math and heavy on descriptive content, making it easy to read and grasp the concepts. Further reading is given for more in-depth technical approaches to the topics, which is welcome for the scientists in the audience. Overall, I highly recommend this book for an introduction to planetary geology concepts.