Noctilucent
The glow of noctilucent clouds (NLCs) in the southern Oregon sky on 9 June 2019. This is a very rare event, most NLCs are limited to polar regions (55 degrees north); these clouds were visible as far south as San Francisco (38 degrees north). The clouds are formed by the smoke (dust and crystals) left behind from meteoroids high in the atmosphere ~85km. Shot with a Nikon CoolPix. ISO 400 1 sec.
—Robert Schalck, Senior Member