TPM predictions of the disk-integrated flux densities as a function of wavelengths for all 22 observing epochs. The central positions of the HIRS IR bands are indicated by dotted lines. The variation in absolute flux density is mainly related to the changing phase angles and, in second order, to the small changes in heliocentric distance and observer-Moon distance. The thermal emission peak lies between 10 and 20 μm, the transition between reflected sunlight and thermal emission is located between 2 and 3 μm. A constant hemispherical spectral emissivity of 0.95 was assumed for these predictions.