“By overlaying the six satellite passes and applying NASA’s night-time algorithms, we can identify large green spots suddenly appearing and gradually fading,” explains Alejandro Sánchez de Miguel, researcher at the Instituto de Astrofísica de Andalucía (IAA-CSIC) and project lead of several ESA-supported initiatives monitoring light pollution from space.

“The green dots indicate the absence of light, while white ones show areas with stable electricity supply. This distribution is consistent with electrical company reports and the gradual return to normality,” adds Alejandro.