Astero-chronology with SDSS
          Zeljko Ivezic, University of Washington
           Mario Juric, Princeton University
           Robert Lupton, Princeton University
           Robert Jedicke, University of Hawaii
           David Nesvorny, Southwest Research Institute
           Robert Whiteley, USAF Space and Missile Systems Center
           Gyula Szabo, Szeged University

          We will describe the multi-color observations of over 200,000 asteroids by the SDSS. In addition to detecting asteroids to a 2 mag deeper limit than other large-area surveys, the SDSS provides valuable color information for over 40,000 previously known asteroids. We will discuss the strong correspondence between asteroid dynamical families and their colors, and the recently discovered correlation between the family age and its mean SDSS color. The age-color correlation is due to space weathering, and offers a new method, termed astero-chronology, to estimate asteroid ages from their measured colors, and study the chemical and dynamical evolution of our solar system.