Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically over the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, this volume outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's.