Flying Object Spotted Over Monument Valley

There is no commentary on the video, except for an unintelligible phrase as the clip opens, so perhaps the photographer may not have been aware of the UFOcaught on tape until it was reviewed later.
The object looks like no known aircraft. It's rounded, silver and shows no lights or markings. It passes at super high-speed, and the video includes two enhanced segments which only help to deepen the mystery rather than explaining it away as a jet or an airplane.
So what is it?
Here's the video:

Source: Gather.com