No, it's neither a drone nor a spaceship.. it's the anemometer measuring the speed of wind on top of our garage roof yesterday afternoon at the time storm "Doris" passed us. To be honest I didn't know our storms were given names, but as it arrived from the U.K. and apparently was called Doris there, it stayed Doris here :)
We don't live near the coast and it was (only) force 7 here, but at the North Sea coast people had to deal with force 9 or 10 and dangerous conditions like heavy wind gusts.
And it rained a lot as well. This photo was taken through an upstairs window towards the line of trees at the back of our garden.