"Les Crossan" wrote in
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I thought 57.5N was just that little too far south for astronomical
twilight to last all night?? After a quick check looks like I was wrong.
Could still be nlc though.. i'll stick to severe weather in future (:


Les


Les

Astronomical twilight does not end until the sun is 12 deg below the
horizon, so at the summer solstice it lasts all night at latitudes north of
54.5 deg.

I doubt whether NLCs contribute much to illimination in these circumstances,
but never having consciously seen one that is just a guess.

Regards, Roger