Experimental and theoretical advances are critical to understand the complex nature of planetary interiors and to provide new constraints on models for planetary origins and evolutions. New experiments elucidate fundamental properties such as melting, structure, partitioning, phase relations, kinetics, transport mechanisms, elasticity, and electronic states of planetary materials. Advances in ultrahigh pressure techniques including dynamic compression and ab-initio electronic structure methods are extending this research to previously inaccessible scales. Moreover, advancements in spatial and energy resolutions, as well as the combination of x-ray and optical methods provide unprecedented experimental access to the extreme pressure-temperature regime of planetary interiors. This session welcomes contributions that highlight cutting-edge developments in experimental and theoretical methods that address the properties of planetary materials and the application of these results to build next-generation models of the formation, interior structure, dynamics, and thermal evolution of planetary interiors.