In which atmospheric layer do Noctilucent Clouds (NLCs) exist, making them the highest clouds?

Answer

The mesosphere, roughly 47 to 53 miles (76 to 85 kilometers) above the surface

Noctilucent Clouds exist in the mesosphere, which is the highest region mentioned for cloud formation, located approximately 47 to 53 miles above the Earth's surface.

In which atmospheric layer do Noctilucent Clouds (NLCs) exist, making them the highest clouds?
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