Early on, our Solar System was a disk of dust and gas in orbit around the proto-Sun. The solid materials collided with each other and accreted to form gradually larger bodies, until the Solar System's four terrestrial planets (Mercury, Venus, Earth, and Mars) were formed. Since the core was forming while the Earth was still growing, we need to understand how pressure, temperature, and composition of the Earth evolved during accretion.
I ran 100 N-body simulations of terrestrial planet accretion to study this process. By running such a large number of them, I could obtain a statistical view of the probabilities of matching different Solar System properties and check for correlations between properties, which were largely absent. The simulations provide information about the mass evolution of the Earth and the provenance of its building blocks, which I then incorporate into a model of core–mantle chemical evolution.
More recently, I have also been using these models to trace the isotopic provenance of Earth, Theia, and Mars. I apply an initial gradient in Ru–Mo isotopes through the disk, then calculate the isotopic compositions of the mantle of the resulting planets. In this way, I can determine what initial compositions are needed to reproduce Earth's zero anomaly, and make predictions of the isotopic anomalies in the Moon and Mars.
NASA Astrobiology Magazine