Noctilucent clouds are glowing clouds that can be seen in parts of the northern hemisphere at night.

Noctilucent clouds, known as NLCs, are glowing clouds that can be seen in parts of the northern hemisphere during summer at night.
They have begun appearing further south and earlier in the season than ever before, which might be an indication of the effects of climate change on the atmosphere of Earth.

These glowing clouds form higher up in the atmosphere than any other kind of cloud.

NLCs were first noticed back in 1885 after the eruption of the super volcano Krakatoa, but even after the ash from the volcano had settled, the clouds remained.

James Russell, the principal investigator for NASA’s AIM satellite used for observing clouds said: “When methane makes its way into the upper atmosphere, it is oxidized by a complex series of reactions to form water vapor, this extra water vapor is then available to grow ice crystals for NLCs.”

Sunrays coming from below the horizon light up the ice crystals, which causes the glowing effects.

Previously, NLCs were only visible in places far to the North like Alaska, and Northern Canada.

Now NLCs have been observed as far south in the United States as Colorado, and Utah.