Most of the details surrounding the planets came from actual travel using spacecraft and probes. The information presented throughout the book has been supported by data from spacecraft and other observations. The data examples used in the book are very valid because tools like a spectrometer were used. This was a well-written book, and it really helps the reader understand how and what the planets are made of. The details provided allow the reader to create a mental image of these planets. Mental image doesn't just involve color or order, this book helps the reader clearly understand what the surface looks like. This book shares the mistakes and mishaps of other NASA workers. Hopefully, the information in the book will inspire future NASA employees to explore more of the universe. After reading this book, they will be more likely to accomplish their mission.