Once while having a broken leg I had to stay pretty calm at home. It was spring, skies were clear and there was nothing to photograph. Until attention was paid to contrails. Some of them showed strange behaviour and formed what I came to call chromosome contrails (samples on page #2). After this incidence this new category was added to my archives. It is not a big thing and does not show too much of variability, but still, it is seen in the sky and so needs attention!
|Nacreous clouds root||Cloud's shadow root|