Sarah Stewart uses computer-based dynamical simulations and lab experiments to create scenarios for the collision of a massive body with the Earth that can reproduce the composition, orbits, and spins of the Earth and Moon today.  
Sarah Stewart is a Professor in the Department of Earth and Planetary Sciences at the University of California Davis.  In the podcast, she explains how, following a massive impact with another body, the Earth formed a synestia - an inflated disk of gas in which the impacting body and Earth were thoroughly mixed, and out of which the Moon and a new Earth solidified.
For podcast illustrations, including videos of simulated Moon-forming impacts with synestias, and orbital simulations, go to geologybites.com.