Because of the Moon s unique place in the evolution of rocky worlds, it is a prime focus of NASA s space exploration vision. Currently NASA is defining and implementing a series of robotic orbital and landed missions to the Moon as the initial phase of this vision. To realize the benefits of this activity, NASA needs a comprehensive, well-validated, and prioritized set of scientific research objectives. To help establish those objectives, NASA asked the NRC to provide guidance on the scientific challenges and opportunities enabled by sustained robotic and human exploration of the Moon during the period 2008-2023 and beyond. This final report presents a review of the current understanding of the early earth and moon; the identification of key science concepts and goals for moon exploration; an assessment of implementation options; and a set of prioritized lunar science concepts, goals, and recommendations. An interim report was released in September 2006.