Why do the stars shine? What happens when you fall into a black hole? What’s the Moon made of? How many planets are in our galaxy? Does extraterrestrial life exist? How old is Earth? Can humans live in outer space? What is a quasar? How did the universe begin? How will it end? When it comes to the cosmos, it seems like everyone has a thousand questions.

Well, you’re in luck—this book has a thousand answers.

Actually, it contains more than a thousand answers to more than a thousand questions about the universe and how it works. These pages contain far more, though, than a mere compilation of facts and figures. Together, these questions and answers tell the story of astronomy—of the cosmos and its contents, and of humanity’s efforts throughout history to unlock its secrets and solve its mysteries.

Since the dawn of civilization, people have tried to understand the objects in the heavens—what they are, how they move, and why. At first, it was a total mystery; our ancient ancestors created myths and stories, and ascribed supernatural qualities to the stars and planets. Slowly, they learned that the heavens and its contents were natural, not supernatural, and that everyone, not just a privileged few, could understand them. Slowly, the science of astronomy was born.

What is science? It sure isn’t a bunch of facts in a big thick book that old folks in lab coats think you should memorize, regurgitate, and forget. Science is a process of asking questions and seeking answers by weighing the facts, making educated guesses, and then testing those guesses with predictions, experiments, and observations. That’s what this book is all about: the unquenchable impulse to ask questions and seek answers. You’ll read about the questions that were asked, the people who asked them, how they tried to find the answers, and what they discovered in the process. We owe what we know about the universe to the tireless work of those questioners—those men and women who laid the foundation of astronomy, who searched at the frontiers of knowledge.

That search goes on today, with just as much joy and curiosity as ever—and you can be part of it, too. In this book, you’ll learn about planets, stars, galaxies, and other amazing celestial objects that you can study. Then, toward the end of this book, you’ll find useful information and tips about how to make your own astronomical investigations. There are star charts, too, that you can take with you out under the night sky. Use them to identify the stars and constellations so you can connect personally with the universe, just as astronomers of all ages all over the world do—and have done since time immemorial.

In modern times, humanity has seen to the edge of the observable universe with ground-based and space-borne telescopes. We have explored distant worlds with robotic spacecraft. We have even started to take our first baby steps into space ourselves. And yet, the more we learn and experience, the more we realize how much we still don’t know. This book contains a thousand answers, and that’s just a start. May those answers lead you to a thousand more questions; and like those scientific explorers who came before us, may you also experience the joy of discovery as you seek—and find—the answers!