Daily mean illumination of 67P (in units of the irradiance received by a point at Earth’s equator, averaged over one rotation, for a distance of 1 AU from the Sun) in the side-by-side layout of the QuACK map projection. The norther hemisphere is to the left and the southern hemisphere to the right. For the relation to the topography of 67P and longitudes and latitudes, see Fig. 9. Top: arrival time of Rosetta at 67P, 8 August 2014, close to summer solstice. Bottom: perihelion, 13 August 2015, close to winter solstice.