In-Situ K-Ar Geochronology: Age Dating for Solar System Sample Return Selection

Abstract

The development of an in-situ geochronology capability for Mars and other planetary surfaces has the potential to fundamentally change our understanding of the evolution of terrestrial bodies in the Solar System. For Mars specifically, many of our most basic scientific questions about the geologic history of the planet require accurate knowledge of the absolute time at which an event or process took place. For instance, what was the age and rate of early Martian climate change faithfully recorded in the mineralogy and morphology of surface lithologies (e.g., [1])? Currently, our only means of assessing the absolute age of a surface on a planetary body is through the use of crater counting statistics. This technique is fraught with uncertainty for planets with active geologic surfaces, on the order of billions of years in some cases (e.g., [2]). Accordingly, there is much room for improvement in our understanding of the absolute chronology of the surfaces of rocky planetary bodies.