Dr Paul Byrne is an Associate Professor of Earth and Planetary Sciences at Washington University in St Louis.Byrne's research focuses on comparative planetary geology—comparing and contrasting the surfaces and interiors of planetary bodies, including Earth, to understand geological phenomena at the systems level. Byrne’s research projects span the solar system from Mercury to Pluto and, increasingly, to the study of extrasolar planets. He uses remotely sensed data, numerical and physical models, and fieldwork in analog settings on Earth to understand why planets look the way they do.