Saw it briefly two times in frame taking pictures then looked back over pics and realized I capt. it tried recreating it with no luck

It was a beautifully clear day on the way back from Vegas. I was flying Spirit Airlines. I was sitting on the left hand side of the aircraft and was looking what would of been NW? I took many many pictures on the way back of all the lakes and snow packs and mountains and deserts. It was closer to WA when we were above a floor of clouds it was breathtaking. The sky was brilliant blue. We came to an area where there were breaks in the floor of clouds which looked like lakes so I was snapping shots. I also notice there was a jet trail in the far distance. I was zoomed in on that area and I noticed a disk like object coming into the frame and then almost vanishing like it was going behind a cloud. I thought nothing of it. A few minutes later I scrolled back through my photos and that's when I had noticed that I caught it in a frame. I zoomed in and was perplexed as to what it could be. I tried recreating the object in pictures afterwards thinking that it could of been a piece of dust on the window or something, but I could not recreate the object at all. I later zoomed in and it was even more bizarre. IT was a silverish disk like object with rings on the bottom of it.