This is so cool, I love watching the sky at night and clouds in the day. I subscribe to a group list from NASA about the sky several times a week emails come which tell all sorts of current events in the sky to watch. These noctilucent clouds (NLC) I discovered a year or so back and I was fascinated by the idea of glowing blue clouds in the dark night sky over northern European cities where they have been reported and photographed. On Space Weather.com the photography and movie galleries are very entertaining and educational. NLC are oh so spooky and happening over the northern latitudes just like the other night time phenomenon I want to see some day the northern lights. I haven't seen either one of them myself but with a little help from NASA I get to imagine it via Internet video and photos from all around the globe, so far we have no national barriers for astronomers.
This video of the entire year of snapshots done by the new satellite sent up to study noctilucent clouds is from 2007 and very inspiring. We are wondering if it is a symptom of global warming that caused these to appear at the dawn of the industrial age.
Read more on the NASA space weather site about sky topics. Today it is about the extra colorful sunsets that have been happening in our country and in northern Europe because of a few volcanos that spewed ash up into the stratosphere on August 7th.