Bray Jacobson 
Ciclos en el espacio (Cycles in Space) [PDF ebook] 

As Earth moves around the sun, the seasons on Earth change. The movement of the moon affects the tides in Earth »s oceans. What happens in space has an influence on our lives. In this book, readers explore the cycles in the space that most affect us and the space science taught in upper elementary science classes. Accessible language and simple explanations make this the perfect introduction to Earth »s cycles for readers struggling with traditional textbooks. Diagrams of each cycle provide a great review of each cycle as well as another way to understand each concept.