Discover the natural force of gravity in this colorful exploration of the phenomenon that affects us all! What's up? What's down? What's keeping you steady? In Gravity: Mass, Energy, and the Force that Holds Things Together with Hands-On Science Activities , scientists ages 8 to 12 explore the invisible but powerful force that is responsible for keeping the entire universe in place--including you! Gravity is the natural phenomenon that makes everything in the universe attracted to everything else. On Earth, that means gravity is why we fall down toward the ground, the reason we have tides, and why we weigh a certain number of pounds. Hands-on STEM activities, entertaining illustrations, essential questions, text-to-world connections, fascinating sidebars, and links to online resources and videos in this book are as forceful as gravity itself! Additional materials include a glossary, a list of media for further learning, a selected bibliography, and index. Aligns with Common Core state standards and Next Generation Science Standards. All books are leveled for Guided Reading level and Lexile and are available in paperback, hardcover, and ebook formats.