Abstract:
Absolute ages for planetary surfaces are often inferred by crater densities, and are only indirectly constrained by ages of meteorites. Cratering chronology models were calibrated only based on lunar samples, and are transferred towards other planets using crater scaling laws and cratering rate ratios. This transfer often relies on extrapolations.

The link between Shergottite meteorites and their source crater Mojave and the K-Ar ages measured at Gale Crater allow for a calibration of the Martian chronology model as well. Thus, the cratering-based age determination method for Mars is now calibrated. This new Martian cratering chronology model is tested against the in-situ determined radiometric and exposure ages for a mudstone in Gale crater, and the ages found with both methods are virtually identical. As a result, Martian surface features dated with cratering statistics shifts the absolute age of the oldest terrains of Mars and Mercury backwards by 200 Myrs. I will discuss the calibrated chronology model with respect to modern solar system bombardment patterns and whether we represent the surface evolution of Mars, Moon and Mercury well.