It's a full moon and a so-called blue moon today, 18th May at 21:11 UTC, I discover. It's "an additional full moon that appears in a subdivision of a year" to quote Wikipedia. See https://en.wikipedia.org/wiki/Blue_moon for details. Before finding out about this I thought the blue moon thing was just an expression. It's overcast and rainy here in Edinburgh, so nothing much to see.