As another work from the popular science series 12 Letters from Scientists to Children, Ouyang Ziyuan, China’s preeminent lunar exploration scientist and CAS member, shares his own experience in studying geology, aerolite, cosmic dust, and samples of moon rocks, and specially introduces Chang’E Lunar Exploration Program and China’s independent Mars exploration. The book’s unique epistolary format transforms complex space science into personal conversations, sparking young readers’ interests in the mysterious universe.