Thermal conductivity measurements of porous dust aggregates: I. Technique, model and first results

► Non-invasive technique for measuring the thermal conductivity of fragile and sensitive materials. ► Measurements provide important knowledge about the influence of heating processes, like internal heating, on the evolution and growth of planetesimals. ► The thermal conductivity was determined by a combination of laboratory experiments and numerical simulations. ► Three types of porous dust samples, consisting of spherical, micrometer-sized SiO2 particles, were investigated. ► The thermal conductivity of the samples with volume filling factors in the range of 15-54% was determined to be 0.002-0.02 W/(m K).