Evolution of subsurface temperature over one orbit of 67P. The temperatures are for the same location on the nucleus as inFigs. 5 and 7. The simulation parameters for the orbit and orientation of 67P are listed in Table 1. The nucleus is assumed to be dry. Results are shown for a conductive nucleus with κ = 0.002 W m⁻¹K⁻¹ (panel a), aradiative nucleus consisting of 1 mm aggregates (panel b), and 1 cm aggregates (panel c). In panel c, the contours are only indicated below 0.1 m because the temperatures in the upper layers display diurnal variations that clutter the contour lines.