• The bulk density and porosity of the upper highland crust are revisited using a high-resolution GRAIL gravity field model (Park et al., 2015) in combination with LOLA topography (Smith et al., 2017) and independently estimated grain densities • Using the estimated bulk densities in combination with grain densities estimated from surface composition, the porosity of the upper crust was determined. Each grid point with a spacing of 0.75 deg was calculated using a circular analysis region of 3 deg radius. The grids are equally sampled following the sample theorem of Driscoll and Healy (1994). • For many impact basins, porosity is reduced within their peak ring and increased near and just exterior to the main rim • Large impact basins show a stronger pronounced porosity signature than smaller basins, and old impact basins reveal a muted porosity signature compared to younger basins