Above US shone the silver clouds

Bright electric-blue clouds spotted in Seattle, Washington.

Noctilucent clouds, which are sometimes called night-shining clouds are the highest clouds of the Earth. It’s a very cold, very sparse and filled with tiny ice crystals clouds hovering at the altitude of about 80 kilometers above the surface of our planet. When the sun rays pass through these ice crystals, clouds are becoming a rich glowing blue color, clearly visible in a deep twilight.