Around this time, the sun never dips far below the horizon, leaving it well placed to illuminate the high-altitude icy particles as night settles in. Noctilucent clouds most commonly appear ...

Noctilucent, or night-shining clouds, are rare clouds that can be spotted shortly after sunset in higher latitudes. Summer is the best time to look for them.

Around this time, the sun never dips far below the horizon, leaving it well placed to illuminate the high-altitude icy particles as night settles in. Noctilucent clouds most commonly appear ...