Interpretation of combined infrared, submillimeter, and millimeter thermal flux data obtained during the Rosetta fly-by of Asteroid (21) Lutetia

► We combine IR (VIRTIS) and smm/mm (MIRO) data to constrain the thermal properties of Asteroid Lutetia. ► VIRTIS dayside temperature measurements in excess of 240 K indicated thermal inertias less than 20. ► MIRO 2-channel polar night measurements indicated a Lutetia thermal inertia increasing with depth. ► Comparisons of model predictions with VIRTIS dayside temperatures indicated roughness effects. ► Addition of a model of 50% coverage of mini-craters resolves the model vs. measurement offsets.