„Oh dear, some kid lost a balloon…
But then on a second thought, that „balloon“ was too round, too fast, moving in a too straight line and looked too „solid“, for lack of a better term….
A balloon, that’s my strong guess.
Was there something locally going on like a maypole festival (which is celebrated today) from which a ballon might have originated?
Quite some years ago by accident I let a ballon loose and watched it go up and was quite fascinating how quickly it didn’t look like a ballon at all anymore if I wouldn’t have known and seen with my own eyes that it is a ballon! Actually, my own eyes started to see it as a UFO very quickly even though I knew it was a ballon! It looked and behaved very „UFO“ like indeed. So that accident was a very educational and enlightening thing to me.
If you get around it, it might be a fun experiment to buy a ballon (or better, several ballons in different colors!) and watch them go up yourself. Depending on the color of the ballon, and things like light and wind conditions, it can look and behave very differently.
To determine the speed of such an object in the sky is very difficult and it is pretty likely that you can miscalculate the actual speed dramatically. In what we see in the video we can’t pin down (or narrow down) the size or distance of the object. Which are two of the primary factors to ascertain speed. The most we can say is that the objects was below the clouds and moved. Which doesn’t help us much either.
Looking at the footage it looks consistent with a ballon to me, including the alleged „fast speed“.
When a ballon reaches a certain height it might encounter air streams that are quite fast (which move the ballon horizontally) and if you don’t know the size or distance of the object, your personal sense of „the speed of the object“ can mislead you greatly.
Edit: More things; Also, on its way up, a ballon likely encounters several different air streams that have different speeds or even different directions of wind speeds?!
So a ballon can likely appear to speed up, slow down, or even change directions rather rapidly (!) as it moves up through the different air layers and wind speeds.
Also, a ballon expands when it goes up in the sky
(they get bigger and ever more sphere like until they burst?). So a ballon can even shapeshift quite dramatically, especially if it is in an unusual shape
to begin with!