Noctilucent Clouds are composed of tiny ice crystals 40 to 100 nanometers wide, which is just the right size to scatter blue wavelengths of sunlight, a NASA scientist explained.
According to NASA, the best time and location to search for these breathtakingly beautiful phenomenon would be between mid-May and the end of August in the northern hemisphere. However, with no explanation yet found, these glowing, mystical clouds have been seen even as far south as Utah and Oregon and Denver, Colorado in the recent years.
Noctilucent Clouds were first observed in 19th century but their appearance has increased over time and are seasonal, appearing most often in late spring and summer every year.
Comment: Let us suggest a reason for why instances of noctilucent clouds are increasing and intensifying.
What we suspect has been happening, based on our research thus far, is that the upper atmosphere is cooling because it is being loaded with comet dust, which shows up in the form of noctilucent clouds and other upper atmospheric formations.
Magnificent and mesmerizing noctilucent clouds (also called polar mesospheric clouds), were once considered to be rare. But now they are puzzling scientists with their recent dramatic changes. Apparently, the clouds are growing brighter, are seen more frequently, are visible at ever lower latitudes and are now appearing even during the day. If scientists were allowed to conduct honest interdisciplinary research, such changes wouldn't be a mystery.
They would be able to figure out that comet dust is electrically-charged which is causing the earth's rotation to slow marginally. The slowing of the rotation is reducing the magnetic field, opening earth to more dangerous cosmic radiation and stimulating more volcanism. The volcanism under the sea is heating the sea water which is heating the lower atmosphere and loading it with moisture.
The moisture hits the cooler upper atmosphere and contributes to a deadly mix that inevitably leads to an Ice Age, preceded for a short period by a rapid increase of greenhouse gases and "hot pockets" in the lower atmosphere, heavy rains, hail, snow, and floods.