Noctilucent Clouds

I woke up early this morning ("in the middle of the night"), turned on the radio and heard FiveLive's Dotun Adebayo say that people were phoning and texting from around the country about tonight's aurora. I was interested. The aurora borealis (or australis) are on my list of things to see before I die. I snuck into my son's north facing bedroom without too much hope; I thought a bright street light near the house would swamp the faint light of the aurora. However, out of the window I could see a bright patch and a bright star or planet. Was this just the sunrise? No; too early - 2:53. So, not a sunrise, but the aurora? I wasn't sure, it didn't really look like the films and photos I'd seen, but on the other hand.....

I turns out that I, and the rest of the UK, were seeing noctilucent clouds. These are very high clouds, illuminated by the sun from below the horizon, visible only around midsummer. Apparently they were only first observered in 1885 but are becoming more common, perhaps as "a miner's canary for global change". And the bright star? Arcturus.