3am. Sometimes, insomnia is useful.
#Noctilucent clouds (NLCs) are made of water ice crystals that form below -120°C (-184°F) and at ≈ 76-85km (47-53mi), the highest clouds in our atmosphere.
NLCs are only visible during twilight and usually summer from latitudes of ±50° and ±70°, and when the lower atmosphere are in Earth's shadow but these clouds are in sunlight.
Text derived from https://en.wikipedia.org/wiki/Noctilucent_cloud
photography group (npub1fcp…w85n)
#Scotland #AtOptics #AstroPhotography #Comet #Astro
