#OTD a year ago, I walked out of my office around 23:30 to ride home & was stunned by the display of noctilucent clouds overhead

I took *a lot* of pictures with my phone: I’ve reprocessed some for the anniversary. Enjoy

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@CloudAppSoc @StormHour
#noctilucentclouds

The first two 21 June 2019 #noctilucentclouds photos here are similar but not the same – you can see the evolution over 2.5 minutes. The third was taken in Katwijk ~35 mins later, as the clouds drifted over the North Sea towards the UK.

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@CloudAppSoc @StormHour – bei European Space Research and Technology Centre (ESTEC)

It was by far the best display of #noctilucentclouds I’ve ever seen: normally they appear low on the northern horizon & even then, they’re rare. That said, it’s said that they’re becoming more common, so keep your eyes open & follow @NLCalerts

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@CloudAppSoc @StormHour

There’s plenty of information online about how these rare highest of ice clouds form at 75-85km altitude & also the remarkable fact that they’ve only been known since 1885. Their increased occurrence may be linked to extra methane in the atmosphere.

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https://en.m.wikipedia.org/wiki/Noctilucent_cloud

And if you have any pictures of #noctilucentclouds, @CloudAppSoc are starting a new gallery of them with @GoStargazing – check out their picture of the month for June (hint: it’s one of mine ) & send them in

5/5 https://cloudappreciationsociety.org/june-2020/