Bright NLC´s

 

Noctilucent clouds are the highest clouds in Earth's atmosphere, forming in the mesosphere about 76 to 85 kilometers (50 miles) above the surface.

Meaning "night-shining" in Latin, they appear as electric-blue, silvery, or glowing wisps during summer deep twilight when they are illuminated by the sun from below the horizon.

Noctilucent clouds (NLCs), also called polar mesospheric clouds (PMCs) when viewed from space, are a tenuous atmospheric phenomenon. Unlike typical weather clouds that form less than 12 miles above Earth, NLCs occur at the very edge of space.How

For noctilucent clouds to form, three precise ingredients are required:

Extremely Low Temperatures: Temperatures in the mesosphere must drop below -120°C to -140°C.Water

Trace amounts of water vapor must be present.

Tiny dust particles are needed, primarily from micrometeors burning up in the atmosphere.

Water vapor freezes onto the meteoric dust to form microscopic ice crystals, which reflect sunlight. Their striking blue color is a result of the ice crystals scattering sunlight in the upper atmosphere.

Noctilucent clouds are a seasonal and latitudinal phenomenon. They occur only during the summer months when the upper atmosphere above the polar regions experiences its coldest temperatures.

Northern Hemisphere: Best viewed between mid-May and mid-August, primarily at mid-to-high latitudes (roughly 45° to 80° North, including northern Europe, Canada, and the northern United States).

Southern Hemisphere: Best viewed between mid-November and mid-February

Photos taken in Vallentuna Sweden 16-17/7 2026.