It's time for your mission to Mercury! Jump in your super speedy rocket to explore Mercury's size, atmosphere, temperature, gravity, orbits, Discovery Rupes, and Caloris Basin. Basic solar system facts are brought to life with a focus on what questions scientists are still trying to solve. Each book ends with a section on how scientists discovered the facts that have been presented. Bright, colorful illustrations and straightforward text make this topic accessible for even the youngest astronomer.