A couple of days ago we have had a fine sunset with noctilucent clouds.
So what is so interesting about noctilucent clouds?.
First of all they are clouds made of ice crystals that are extremely high up (75-85 km according to wikipedia). They can only be seen around twilight since they are then illuminated from underneath by the Sun that has already set. They are mostly seen from highish latitudes (50-70 degrees – I am at around sixty degrees). They are fairly uncommon.
Revisited because of my previous (failed) attempt to capture noctilucent clouds.