My current research interests include the geology, geophysics, and geomorphology of the terrestrial planets and other solid solar system bodies (particularly asteroids, comets, and planetary satellites), specializing in impact cratering, regolith generation, and other surface processes. This interest has led to multiple lines of scientific investigation, utilizing spacecraft and ground-based radar observations, laboratory impact experiments, and analytical and numerical modeling techniques to answer outstanding questions regarding the surfaces, internal structure, and developmental history of these objects.
- Described the erosional process whereby spin and gravity combine to minimize topographic relief on asteroid surfaces (Icarus, 2014)
- Determinted the surface properties of comet 9P/Tempel 1 via measurements of the crater produced by Deep Impact (Icarus, 2013)
- Solved the long-standing question of how crater density equilibrium is reached on heavily-cratered terrains (Icarus, 2009)
- Determined the density of comet 9P/Tempel 1 via the expansion rate of the ejecta plume produced by Deep Impact (Icarus, 2007)
- Linked the paucity of small craters on asteroid 433 Eros to the effects of impact-induced seismic shaking (Science, 2004, Icarus, 2005)
- Extracted surface features of Saturn's moon Titan hidden within the Orange-fliter images taken by Voyager 1 (Icarus, 2004)