How did life begin on Earth? Does it exist elsewhere? What would those life forms be like? These fundamental questions about the nature of life and our own cosmic significance are endlessly fascinating. In this book, we present several theories on the origin of life, some of its extreme and surprising forms, and the ongoing search for signs—or sentience—on distant worlds.

How did life begin on Earth? Does it exist elsewhere? What would those life forms be like? These fundamental questions about the nature of life and our own cosmic significance are endlessly fascinating. In this book, we present several theories on the origin of life, some of its extreme and surprising forms, and the ongoing search for signs—or sentience—on distant worlds.

How did life begin on Earth? Does it exist elsewhere? What would those life forms be like? These fundamental questions about the nature of life and our own cosmic significance are endlessly fascinating. In this book, we present several theories on the origin of life, some of its extreme and surprising forms, and the ongoing search for signs—or sentience—on distant worlds.