How does the Sun shine? What's at the centre of our galaxy? Why do comets leave long, glowing tails? Read about planets, moons and stars. This book explores out how they formed, how we study them and whether or not anything else out there is alive. This book is part of the Science is Everywhere series, which demystifies the key science topics and shows how they relate to the world around us with fun, colourful graphics. These books are ideal for children aged 9 plus who are studying science, or for young readers who want to get to grips with science in a fun way.