From Orbits to Craters: Modeling the Solar System with Swiftest and Cratermaker

The formation of terrestrial planets involve processes that occur over a tremendous range of size and time scales, which introduces fundamental challenges to our ability to build useful numerical models of planet formation. I will review efforts to model collisional evolution in n-body integrators used in planetary science, including a new model developed within my research group called Fraggle. Fraggle is part of the Swiftest software package, which is an updated version of the Swift n-body integrator package that includes a number of improvements, including improved parallelization and a Python-based front-end. I will show how collisional fragmentation plays a role in the late-stage of terrestrial planet formation and how cratered surfaces can provide important constraints on the dynamical evolution of early planetesimals and collisional fragments. Cratering is arguably the most common geologic process that occurs across the solar system. Cratered terrains occur on nearly every solid surface from small asteroids, to rocky planets, rocky and icy moons, and distant Kuiper belt objects. For more than a decade, my research group at Purdue University has been studying how impact cratering shapes planetary surfaces using a landscape evolution software code called the Cratered Terrain Evolution Model (CTEM). CTEM was originally written to investigate the problem of crater equilibrium, but has proven itself to be a useful tool for investigating a variety of problems in cratering science, including: investigating the influence of seismic shaking on asteroid craters, testing models for the size-frequency distribution of ancient lunar impactors, studying the transport of material across highland/mare boundaries, investigating regolith production and evolution, determining the processes that set the equilibrium size-frequency distribution for small simple craters, and modeling the age distribution of impact melts Apollo surface samples. Recently, my group has developed a new tool called Cratermaker, which is aimed to be a replacement for the venerable old CTEM but is easier to use, easier to modify, and includes a number of significant improvements over CTEM. In this talk, I will review some of the work we have done using the CTEM code, demonstrate the current capabilities of Cratermaker, and discuss the capabilities that are currently being developed.