This was
your sky.

Nacreous Clouds over Sweden

These vivid, iridescent clouds are called nacreous clouds, also known as mother-of-pearl clouds. They are rare, forming when temperatures in the lower stratosphere become unusually cold, allowing ice crystals to form. This photograph from northern Sweden captures their unforgettable appearance with the Sun just below the horizon, illuminating them at altitudes of 15 to 25 kilometers.