The hidden side of energy saving: rural Spain is turning blue at night

A high-resolution map using SDGSAT-1 data shows many small towns in rural Spain and the Iberian islands replacing warm streetlights with blue-toned LED lamps.

The shift cuts energy use, but it can also increase night sky glow, making astronomy harder and affecting wildlife and biological rhythms.

The map, developed with RALAN-Map EU and researchers including Alejandro Sánchez de Miguel, helps track lighting changes and guide better streetlight management.