Titan's young surface: Initial impact crater survey by Cassini RADAR and model comparison

Cassini's Radar instrument has mapped over 10% of Titan's surface through the T18 flyby in August 2006 and has detected remarkably few impact craters. Three impact craters have been conclusively identified and named, and a handful of unconfirmed candidate impact structures are documented. These results indicate that the overall crater density is a factor of similar to 5 higher than Earth, and has a size-distribution slope very similar to Earth's indicating rapid obliteration of smaller structures by erosion and burial. The paucity of small craters was expected from atmospheric shielding considerations, but the rarity of medium (20-100 km diameter) craters - some 30-300 times less abundant than on nearby Saturnian satellites - implies rapid resurfacing. Erosion and burial appear to be the dominant means of crater obliteration, with viscous relaxation playing a lesser role. Models of the 20-100 km impact crater production rate suggest an overall crater retention age of 100 Myr-1 Gyr, the same as the corresponding age for the Earth.