Exo-comet populations and their impacts on atmospheres

Using N-body dynamical simulations I will model the potential impacting populations of asteroids, comets and other bodies left over from planet formation onto planets early in their lifetimes. This can be done for both the solar system as we understand it currently and for hypothetical exoplanetary systems. The results of these simulations will provide the input for simulations of dust production by collisions (to be done by another student) to model zodiacal and exo-zodiacal dust. The predictions about the dust can then be compared to observations in order to constrain model parameters.

The results of the N-body simulations will also have the potential to be used in work investigating the effect of impacts on the growth or depletion of planet atmospheres. To do this I will use existing analytical prescriptions for how atmospheres grow and deplete in response to impactors of different types to create a model for how these atmospheres will evolve with time. This can be applied to planets within our solar system and to exoplanetary systems. I intend to extend this work to include the effect of giant impacts also. This will have implications for the potential habitability of these worlds.

This work has the potential to progress in several different directions, dependant on the rate of progress and conclusions reached. One of these could be to investigate the effect of outwardly scattered planets on systems with an exterior debris disk, trying to recreate a system similar to Fomalhaut-b or q1Eri. Another possibility is to look at comparing planet formation mechanisms by modelling the evolution of observable signatures (levels and lifetimes of dust as well as mass transfer between planets) produced by the evolution of debris that would result from the breaking of a resonant chain of super earths.