This book describes a 5-day program of imaginative activities designed to help elementary school children learn how their world functions through seeing, smelling, tasting, touching, and hearing. The book is designed to help children understand energy flow, the cycles of basic materials, the diversity of life, natural communities, change, adaptation, and interaction among living things and their surroundings. The "acclimatization" program includes many activities, sequentially ordered, using the comparison of our planet to a spaceship, with the sun as primary energy source. Chapters 1 and 2 explain the Sunship Earth idea and its operating principles. Chapters 3 and 4 explain the model and summarize the program, including timetables for a 5-day resident experience. Shorter, nonresident experiences are also presented. Chapters 5 and 6 offer preparation guides for students and teachers. Chapters 7-9 describe a series of make-believe activities and present the learning guidelines that drive them. Activities in Chapters 10-12 are intended to help students feel closer to nature; those in Chapters 13-15 are designed for afternoon hours, evenings, and rainy days. Activities described in Chapters 16-20 include community meetings, cabins and crews, meals and snacks, quiet times, and campfires. Chapter 21 describes an activity in which children are encouraged to design a model planet. Activities in Chapters 22-24 include a "Sunship Meeting,""Passengers Guide," and a closing ceremony. There is a six-page index. (TES)