In a companion to Sun! One in a Billion, an anthropomorphic Moon--rendered by Lewis as a friendly figure with doe eyes and a sweet smile--announces that it is BFF's with Earth (an equally affable figure who shows its appreciation for Moon with a tender half hug). "We have been together since the beginning. Almost," Moon begins. It describes how it came into existence (from a giant impact with "baby Earth"), explains the moon's phases, and details the way that gravity "pulling on Earth's oceans" causes the tides. Moon provides facts about itself and about various planets and their moons, while clearing up misconceptions and myths (it doesn't go away during the day, and cows don't jump over it). McAnulty conveys complex concepts in a gentle, clear manner that provides readers with a solid foundation for learning more about the galaxy. Ages 4-8. (June)Copyright 2019 Publishers Weekly, LLC Used with permission.