Every year for about 6 weeks we get the opportunity to see Noctilucent Clouds... 3 weeks either side of the Summer Solstice. They happen about an hour after sunset and an hour or 2 before sunrise. On Thursday they were so bright they actually lit up our bedroom. They are WAY up in the Northern sky... About 250,000 to 300,000 feet above the earth's surface. Still images are nice, but I really enjoy watching them on time lapse. Here is a panorama image from Cam 2 and Cam 3.
Here is a time lapse. I like watching the spider web type tentacles that grow on the horizon.