Good bye, blue sky. UBVRI Night Sky Brightness at ESO-Paranal during sunspot maximum F. Patat - ESO Photo by Leo[p]ardo Vanzi-ESO.
Good bye, blue sky
![Good bye, blue sky. UBVRI Night Sky Brightness at ESO-Paranal during sunspot maximum F. Patat - ESO Photo by Leo[p]ardo Vanzi-ESO.](https://static.fdocuments.us/doc/330x215/56649e685503460f94b64f5a/good-bye-blue-sky-ubvri-night-sky-brightness-at-eso-paranal-during-sunspot.jpg)
