Reflected fluxes F, Q, and U, and the direction of polarization χ across the planet and the moon at α=0° (panel a) and 50° (panel b). Fluxes Q and U, and χ are defined with respect to the scattering planes of the planet and the moon, respectively. In order to facilitate the interpretation of the direction of polarization, we plot 180° − χ. Fluxes Q and U are zero across the moon’s disk because of the Lambertian reflection. All fluxes have been normalized such that the disk-integrated flux F at α = 0° equals the body’s geometric albedo. Absolute planetary fluxes per pixel are not comparable to their absolute lunar fluxes per pixel because of the different number of pixels across each disk.