Asteroids are the leftover building blocks that accreted to form the terrestrial planets. As such, they tell us about the initial conditions that existed in our solar nebula some 4.6 Gyrs ago. In particular, their density and internal structure result directly from their place and time of formation. Large asteroids with satellites represent the best opportunity to probe these fundamental parameters, and high-angular resolution imaging techniques provide the most effective tool to study these objects without visitation. I will discuss how recent developments in instrumentation and image processing techniques have allowed us to improve our understanding of asteroid shapes, internal structure, and satellite dynamics, as well as what this improved understanding can reveal at a population level.