Comparison of images before and after the lights-out event in Andacollo, Chile

The lights of the town of Andacollo, Chile were visibly reduced (left) during the Blackout for Our Skies event, as seen from Cerro Tololo Inter-American Observatory. After the event (right) the level of light pollution returned to near normal levels.

Credit

CTIO/NOIRLab/NSF/AURA/D. Munizaga