These clouds are a relatively rare atmospheric phenomenon, extremely rarefied clouds, arising in the mesosphere under the mesopause (at an altitude of 76-85 km above the Earth's surface) and visible in deep twilight. Observed in the summer months at latitudes between 43 ° and 65 ° (north and south latitude). It was possible to prove that similar phenomena take place on other planets, in particular, on Mars.
Forrest White got a reaction from CA3LE in Mysterious glowing clouds targeted by NASA