Robert Gardner 
Planet Earth Science Fair Projects, Using the Scientific Method [PDF ebook] 

Does Earth turn? How does the Moon’s appearance change? How can you accurately map an outdoor area? Our planet is a great place to start experimenting. The simple projects in this book will help young scientists begin to understand Earth, including its place in the solar system, its atmosphere, its only natural satellite, the Moon, and its resources and geology. For students interested in competing in science fairs, this book contains great suggestions and ideas for further experiments.