The Earth is not the world it once was, and it is not the world it will always be. This book describes the exciting, complex, and occasionally baffling history of our own planet. Over the course of its 4.5 billion years, Earth has undergone astonishing changes to its surface and atmosphere, at times more closely resembling other planets in our Solar System than the habitable, teeming biosphere of today. Through these otherworldly analogs, author-illustrator Michael Carroll teaches readers about different aspects of our own planet's past. Our nearest cosmic neighbor, Venus, offers insights into Earth's own young atmosphere and surface, while Saturn's moon Titan may offer a window into the genesis of life on Earth. Planet Earth, Past and Present explores these and many more connections. Original art accompanies each chapter, depicting major stages of the Earth's evolution and providing vivid comparisons to other planets or moons. Come along on this journey through the Solar System--a journey that ultimately leads us home.