This is a rare phenomenon known as cloud iridescence.

Forming 50 miles above Earth's surface, noctilucent clouds offer a rare glimpse into one of the least-understood layers of ...

THE blue color of the sky on a clear day is familiar to all. And yet how many have considered the source of this delicate mantle of azure which Nature spreads over the dome of the heavens? The ...

As summer gets under way in the Southern Hemisphere, electric blue clouds seeded by meteor dust begin to glow high in the sky over Antarctica’s vast icy reaches. This year, according to NASA, these ...

Clouds come in all shapes and sizes, but one of the rarest forms where clouds seemingly shouldn't exist at all: nearly 50 miles above Earth's surface, at the edge of space. "Noctilucent clouds are the ...