Heat conductivity of L chondrite material. (a) Heat conductivity by phonon-transport for the bulk material as calculated from its composition (black line), conductivity for a porous material with a 25% porosity (red line), and conductivity for material with increased phonon scattering by micro-cracks (blue line) with phonon scattering length reduced by a factor s = 30. The dashedline shows the contribution of radiative transfer to heat conductivity. (b) Comparison of the theoretical model (Gail & Trieloff 2018) for L chondrites (black lines) to measured heat conductivities of three L6 chondrites from Opeil et al. (2010, 2012; blue circles) by fitting the model parameters’ porosity (due to isolated pores) and scattering enhancement factor (accounting for micro-cracks).