Have you ever stood in your back yard gazing at the Moon and wondered about the origin of its various features? What makes part of it dark? Light? Smooth? Rough? As old as the Earth, the Moon seems cold and obscure, orbiting in its naked environment more than 356,000 km away. Yet, as scientists have shown us, and returned mission data have confirmed, the Moon is rich with information. Many refer to the Moon as a Rosetta stone, believing that it holds the keys to understanding the origin and evolution of our Solar System.