Shining Metallic Solid Orb

I live below an active airfield and enjoy watching planes and helicopters crossing overhead. I've become skilled at telling which is which as they pass over and what directions they will usually come from, as well as some "regulars" who have private planes in the air. From time to time, I will check an unknown or new plane out on flight radar. Late in the evening. when the light starts to turn golden. I was watering my garden and watching the sky for any late planes and saw a low-flying, silent object in the sky. It was perfectly round and moving very smoothly and rapidly. It was moving against whatever wind I was feeling then and did not appear to have the bob-and-weave motion of a balloon that would have been as high up as it appeared to be. I attempted to get a photo, but when I looked down to grab my phone, the object either rapidly disappeared behind the tree line or outright disappeared as I was unable to observe it again. To me it looked perfectly round, but I had a sense it was flat or ellipsoid and was gold in color. Like a soap bubble, but massive. I suspect it was only reflecting the color that was being shone from the sunset.