Delivery of Organic Material and Water through Asteroid Impacts

Meteorites, specifically carbonaceous chondrites, are frequently invoked as the primary source of Earth's water and organic materials, crucial ingredients for the formation of life. We have started developing a dynamical model of the delivery of their parent bodies, primitive low-albedo asteroids, from the asteroid main belt to Earth and to other planetary surfaces.Existing modeling work focuses on time-integrated delivery rates, which are dominated by the Solar System's turbulent youth. We, in turn, aim at calculating instantaneous delivery rates for comparison with instantaneous measurements. In doing so, we take direct account of the asteroid main belt's observed dynamical and physical structure. In particular, we use low albedo (as taken from the WISE catalog) as a proxy for primitive composition.Our first goal is for our model to reproduce the measured rate of micro-meteorite impacts on Earth. We will then calculate improved delivery rates to Mars and other planetary surfaces within the Solar System.Finally, we aim at applying our model to select exo-planetary systems. Far-IR observations of Vega and Fomalhaut reveal the presence of asteroid belts around these stars; dynamical calculations suggest that those are not a rare occurence but should occur rather generically around the location of the frost line. In such planetary systems, asteroids could deliver water and organics to the habitable region. In this sense, our model should lead to the definition of benchmark observables for exoplanet studies using upcoming/proposed IR facilities such as SPICA, METIS, and JWST.