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night shining clouds | |||
noctilucent clouds | |||
nocturnal clouds; night shining clouds (Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. They consist of ice crystals and are only visible during astronomical twilight. Noctilucent roughly means "night shining" in Latin. WIKI wikipedia.org); nocti lucent clouds |