Posted by KeighleyAstro on Jun 24, 2019 in Main |

These images were taken by society members on Friday 21st June 2019. In the night sky over Yorkshire around 11pm.

They 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. They are most often observed during the summer months from latitudes between 50° and 70° north and south of the Equator. They are visible only during local summer months and when the Sun is below the observer’s horizon, but while the clouds are still in sunlight. Recent studies suggest that increased atmospheric methane emissions produce additional water vapor once the methane molecules reach the mesosphere – creating, or reinforcing existing noctilucent clouds.