I am interested in the thermo-chemical structure, dynamics and evolution of the interiors of solid planets and moons, including Earth, Venus, Mars, Mercury, Io and extrasolar super-Earths, focussing particularly on convection in the solid mantle and the associated dynamics of the lithosphere, which on Earth means plate tectonics. My main research tool is numerical simulation, using state-of-the-art numerical methods on high performance (massively-parallel) supercomputers to obtain more realistic, three-dimensional numerical models of dynamical processes than previously possible.