SIGHTING REPORT UFO sighting at Over the Salt Lake City Valley

I was directly under it when it first saw it! There were no lights on it. It was difficult to tell how far away or off the ground it was. I had been running on the local High School track, and was resting on the bleachers(laying on my back)waiting for my wife and son to finish. I was noticing what a clear night it was, when stars began disappearing from my view. I look closely and noticed that a large "blacked-out" area in a perfect trianglular shape was moving quickly over head. It made no noise. We are near the approach path for the SLC Int'l airport and am used to planes low overhead, but this had to be fairly low too (and large). It moved quicly and silently from the N.W., because by the time I called for my wife and son to get over to me, it was nearly to the S.E. horizon and gone from view. The city lights also caused a problem following it as it got further away.

No, speed was constant.