Noctilucent clouds: an ongoing discovery
Jul 15, 2021
3 minutes
octilucent clouds (NLCs) are the highest clouds in the atmosphere and we can see them around astronomical twilight in a summer’s night sky. The name comes from Latin, meaning ‘night-shining clouds’, and they occur when the Sun is below the horizon and the clouds are still in sunlight. Although no one as yet fully understands why, this appears to be a relatively new phenomenon first seen in 1885 and with an increased frequency
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