Thursday 16 July 2009

Polar Mesospheric Clouds a long way South

On our observatory meeting night, we were treated to the usual clouding over and sprinkling of rain, while we were inside chatting. I was upstars in the dome, hoping we would be able to see a star or have something to point the scope at. We were watching a clear patch start to roll over revealing the twlinkly red star Antares and there were some cirrus-like clouds appearing right across the sky as the twlilight was fading at about 22:00 BST. I presumed they were cirrus but as the sky grew darker I realised they had some wonderful wave like patterns in them, and they continued to stand out from the darkening sky. They were Noctilucent clouds, covering the whole sky at 52 degrees North! I ran to the car while they faded to fetch my Canon 350D and took a few shots with it resting on a chair seat on the observatory roof, pointing NW. This particular shot taken at 22:36 on 15/07/09 is 1/5 second at ISO 1600, f/5.6 and about 35mm focal length (48mm @ 35mm-equivalent) with auto dark subtraction on. I continued at 4 seconds and ISO 100 thereafter for better noise, but the composition and scale of this earlier display looked the most impressive.

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