Assessing the Relationship between Crater Depth and Diameter on Mercury with Topographic Measurements by Messenger

WITH TOPOGRAPHIC MEASUREMENTS BY MESSENGER. Olivier S. Barnouin-Jha1, Maria T. Zuber2, Jürgen Oberst3, Frank Preusker3, David E. Smith4, Gregory A. Neumann4, Sean C. Solomon5, Steven A. Hauck, II6, Roger J. Phillips7, James W. Head, III8, Louise M. Prockter1 and Mark S. Robinson9, 1JHU/APL, Laurel MD 20723; 2Dept. of Earth, Atmospheric, and Planetary Sciences, MIT, Cambridge, MA 02139; 3DLR, Rutherfordstrasse, 2, 12489 Berlin; 4NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771; 5Dept. of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015; 6Dept. of Geological Sciences, Case Western Reserve University, Cleveland, OH 44106; 7Planetary Science Directorate, Southwest Research Institute, Boulder, CO 80302; 8Dept. of Geological Sciences, P.O. Box 1846, Brown University, Providence, RI 02912; 9School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287. Introduction: Several factors influence the shape of craters when they are first formed. These include the density, strength, porosity, nature of porosity (macroversus micro-porosity), heterogeneity, and curvature of the target surface [e.g., 1-4]; the mass, velocity, and impact angle of the projectile [e.g., 2, 5, 6]; and the surface gravitational acceleration [e.g., 7]. The dimensions of craters traditionally used to investigate these influencing factors [e.g., 8] include the crater diameter, D, the diagonal distance between rimcrests, and the crater depth, d, the difference in elevation between the average height of the rim crest and the deepest point in the crater.