Spherical-shaped UFO over O'Fallon, Missouri

On September 19, 2016, a man looked up in the sky when he have spotted a white spherical-shaped UFO over the city of O'Fallon, in the state of Missouri, USA.

Witness statement:

About a month ago my wife and I saw something very similar to this. I went into the house to get my camera. When I came back it was no longer there.
Today, 9/16/16, we witnessed the same thing. We were relaxing outside on our patio and I looked up. There was a white dot in the sky. It was pretty much stationary. I asked my wife to get my camera. It had not moved and I went back in to get my telephoto lens. A 55 to 300mm zoom.
I took several pictures of the object. Not having anything for size reference I could not determine the altitude that it was at. The sky was perfectly clear and what struck me interesting was that there was not air traffic the whole time we were outside. We were outside for approximately 45 minutes. We went into the house to prepare dinner. I checked on it several times and it was still visible. So the entire time it was directly overhead was probably an hour. I stopped looking at that time.

It was silent and appeared to be stationary. It did move from the west to the east over the hour we watched it. If I were to estimate the distance it traveled in that timeframe...I would put it at 1 to 2 miles at the most.

Our dogs were outside with us and showed no behavior change or even sensed what we were seeing. I used a Nikon 12 mp camera with the telephoto to take the pictures. I probably shot over 100. It was just so slow moving that I took several in hopes of getting some clear images.

I thought it might have been a weather balloon. It moved so slowly that I felt it probably wasn't a balloon. I am attaching several pictures for your review. Maybe its a balloon...maybe not.