Night-sky luminance maps in Hammer–Aitoff equal-area projection (in cd m⁻², logarithmic color scale) for a perfectly absorbing surface (α = 0.0), a mean ground albedo (α = 0.2), and a highly reflective (snow-covered) surface (α = 0.8), computed for aerosol optical depth τ_a = 0.3 and aerosol asymmetry parameter g = 0.6. Left: an observer located at a horizontal distance of R =  5.4 km from the axis of the light cone produced on the ground by a 54 m mirror in Earth orbit, shining straight down onto the surface. The radius of the directly illuminated area is 2.5 km, so the observer is roughly 3 km from the edge of the lit portion of the ground. Right: the same situation, but for an observer 14.1 km from the center of the illuminated circle on the Earth’s surface.