noctilucent clouds can be as high as 85 thousand meters
They can be so high that they destroy the sodium layer (not good for laser guide stars)- but noctilucent clouds get more rare as you approach the equator....
Space/Science » in reply to Look up noctilucent clouds
They can be so high that they destroy the sodium layer (not good for laser guide stars)- but noctilucent clouds get more rare as you approach the equator....