Bluish semicircle, flying fast, making absolutely no sound

The UFO was flying low and fast between nimbus clouds. It was a bluish semicircle about as big as the top of my little finger nail in my field of vision, about 70 degrees above the horizon in the North-West portion of the sky. The edges of the object were difuse and it made absolutely no sound. I saw it while standing in my backyard. There was no storm activity. I am 64 years-old and this is the first time I have ever seen anything like it. I was in the USAF and am acquianted with aircraft, balloons, Starlink, but have never seen anything like this. We have no active swamps (It's now winter and dry). We're at 42 degrees, 36 minutes North and 84 degrees 7 minutes West.