Frost feathers

Yesterday's blip was taken as the sun rose. Today's is taken at the other end of the day. It's around an hour after sunset and there is a little light left in the sky, but several lights are on on in the village and outside our house.
The 15 year-old heaty exchanger in Betty's is struggling with these minus twenties and the temperature insid has sunk to just +6°C, so I was up there fixing a "frost guard" heater under the sink to stop the incoming water from freezing.
I noticed these frost feathers on the window and took a few experimental shots. I was very happy with this one!