These are the clouds of the 21st Century.

Picton, NSW, Australia, 7th November 2013

My dad worked for the airline so I was pretty keen on jets. I would watch them fly over the school on their way to land at Kingsford Smith Airport. I could name them. Noisy DC9s with their sooty trails, DC10s with the distinctive tail mounted engine, 727s and double decker Jumbos. I knew all the markings too. Ansett, TAA, BOAC, PanAm, JAL and of course QANTAS.
Later for fun, we would climb the reservoirs. Coogee and Waverley, you could see forever. We watched the planes fly in from all directions up there.

I bought a book about clouds. I like clouds.

All the time I was looking up I never saw clouds like these clouds. These clouds start as trails from aircraft and the wind spreads them across the sky. No aircraft did that when I was a child. They left ice trails which dissipated and vanished leaving the blue canvas of the sky untainted and as beautiful after they flew over as before.