While compiling a brief report on the devastating hail storm of May 8, 2017 over Denver, CO, I came across this photo (attached) looking NNW across Buckley AFB at the approaching storm. Buckley is the primary US missile tracking station.
If you look above the left side of the geodomes on the site, close to the top of the photo, there is an apparent UFO that looks like a disc, edge on, angled at approximately 45*. On magnification it appears to have a central dome and retains its clean lines. This is looking in the general direction of Denver International Airport. However, I have been a professional observer of aircraft for many years from control towers as an air traffic controller and I don't recognize that UFO as an aircraft. If it is a set of wings, there is no tail assembly and the angle of bank is severe for a commercial aircraft.
I am not the owner of this photograph - it was sent to TV station KDVR who published it without acknowledgement. mufon cms# 84753 UFO report Aurora CO. May 8th 2017