What keeps us from floating away? Earths gravity! This invisible force keeps our feet on the ground and the moon in our sky. This title introduces young students to the awesome power of gravity, on our planet and in the black holes in galaxies far away. Narrative openings surround readers with the science around them. Photo labels visually define glossary terms and other important words. Infographics offer additional insight into concepts that are tough to grasp. Simple experiments help the readers test the topic on their own.