XO, Exoplanet is a charming chapter book that introduces young readers to the concept of exoplanets through the delightful personification of our solar system's planets. When Jupiter discovers a new planet orbiting a distant star, the other planets join in to compose a letter. However, a humorous disagreement arises as they try to identify the true exoplanet. This book gently explores themes of curiosity, teamwork, and resolving conflict, making it a fun read-aloud for younger children and an engaging independent read for early elementary students interested in space.