Every 10 years the National Research Council releases a survey of astronomy and astrophysics outlining priorities for the coming decade. The most recent survey, titledNew Worlds, New Horizons in Astronomy and Astrophysics, provides overall priorities and recommendations for the field as a whole based on a broad and comprehensive examination of scientific opportunities, infrastructure, and organization in a national and international context.Panel Reports?New Worlds, New Horizons in Astronomy and Astrophysicsis a collection of reports, each of which addresses a key sub-area of the field, prepared by specialists in that subarea, and each of which played an important role in setting overall priorities for the field. The collection, published in a single volume, includes the reports of the following panels:Cosmology and Fundamental PhysicsGalaxies Across Cosmic TimeThe Galactic NeighborhoodStars and Stellar EvolutionPlanetary Systems and Star FormationElectromagnetic Observations from SpaceOptical and Infrared Astronomy from the GroundParticle Astrophysics and GravitationRadio, Millimeter, and Submillimeter Astronomy from the GroundThe Committee for a Decadal Survey of Astronomy and Astrophysics synthesized these reports in the preparation of its prioritized recommendations for the field as a whole. These reports provide additional depth and detail in each of their respective areas. Taken together, they form an essential companion volume toNew Worlds, New Horizons: A Decadal Survey of Astronomy and Astrophysics. The book of panel reports will be useful to managers of programs of research in the field of astronomy and astrophysics, the Congressional committees with jurisdiction over the agencies supporting this research, the scientific community, and the public.