Clouds are not usually the most enthralling part of nature. But in the late spring and summer, weather conditions conspire to create noctilucent or ‘night-shining’ clouds, high-altitude clouds that glow with an electric-blue hue long after the Sun has set.
It used to be that you could only see these shimmering cloud formations, called noctilucent clouds, if you were in the North or South Pole. But lately they've been on the move, and though they're pretty to look at, their presence away from the Poles may be sign of climate change.
Every year around this time, mysterious electric blue clouds appear over the North and South pole. They are called noctilucent clouds and they can only be seen in deep twilight, when the Sun is below the horizon. According to NASA, "their origin is still largely a mystery":