In the Delta Science Reader Water Cycle, students read about why Earth is called the water planet. They find out about salt water and fresh water and where each kind of water is found. They observe how water changes form by freezing, melting, evaporating, and condensing. They trace the water cycle and find out how heat energy from the sun is related to the water cycle. They learn how Earth’s weather is affected by the water cycle. They also read about Luke Howard, the scientist who first classified clouds. Finally, students investigate water as a natural resource.