Amazon.com description: Product Description: How did our knowledge of Earth's systems, cycles, and resources develop? Who first proposed theories about the solar system, lunar phases, and gravity? And who used those early findings to expand and even change our understanding? Readers will trace the history of key discoveries in earth and space science as they investigate timelines and gather key details from the text. In doing so, s students will make connections between the work of various scientists and analyze the long-term effects of their discoveries.