Tuesday, 8 July 2014
Five hours after seeing the rainbow described in my last post I was outside watching the sky again, this time to look at the strange phenomena of noctilucent clouds. Now whilst I do sometimes wander out during the night to observe the sky this was not a random chance. I was alerted to the clouds by a Tweet from Wendy @benjiandblossom with an impressive picture of noctilucent clouds over Inverness-shire. That's not far away so I was soon outside to an amazing sight. The northern sky was a mass of bright white swirls and streaks that rose from the horizon before fading into the dark blue of the night sky.
Although I'd heard of noctilucent clouds before I had to check just what they are. It turns out not that much is known about them. The key factor though is that they are far higher in the sky than other clouds, around 80 kilometres up, which means that in northern latitudes in summer the hidden sun lights them from below. Of course the night isn't dark for long at this time of year. I started watching the clouds at 1.30 a.m. By 2.30 they were fading as the sky began to lighten. In the photograph you can just see a few stars. It really was dark and I needed a headlamp to move about safely.
The clouds are mysterious and strange. The name is wonderful. Noctilucent just rolls beautifully round the mouth.
Photography note. I used a tripod of course. Camera and lens were again the Sony NEX 7 with 16-50mm lens at 16mm. Details of this image: 1 second at f8, ISO 800.