Title : Optionnel

Text : Noctilucent clouds, or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. When viewed from space, they are called polar mesospheric clouds (PMCs), detectable as a diffuse scattering layer of water ice crystals near the summer polar mesopause. They consist of ice crystals and from the ground are only visible during astronomical twilight. Chaque paragraphe sera un test.

Save test : Utilisez cette option si vous souhaitez partager ce test de dactylographie (uniquement pour les utilisateurs authentifiés).