Titan's global crater population: A new assessment

We report a revised crater population for Titan using Cassini RADAR data through January 2010 (flyby T65), and make a size-dependent correction for the incomplete coverage (similar to 33%) using a Monte-Carlo model. Qualitatively, Titan's landscape is more heavily cratered than Earth, but much less than Mars or Ganymede: the area fraction covered by craters is in fact comparable with that of Venus. Quantitative efforts to interpret crater densities for Titan as surface age have been confounded by widely divergent crater production rates proposed in the literature. We elucidate the specific model assumptions that lead to these differences (assumed projectile density, scaling function for simple crater diameter, and complex crater size exponent) and suggest these are reasonable bounding models, with the Korycansky and Zahnle (2005) model representing a crater retention age of similar to 1 Ga, and the Artemieva and Lunine (2005) model representing a crater retention age of similar to 200 Ma. These estimates are consistent with models of Titan's evolution that predict a thickening of its crust 0.3-1.2 Gyr ago. (C) 2011 Elsevier Ltd. All rights reserved.