Unusual UFO appeared over Deer Valley, Arizona

On December 20, 2017, a witness was taking pictures of unusual cloud in Deer Valley, Arizona. But, after viewing images, he noticed an unidentified flying object...

Witness report:

I went to the park over in Deer Valley (Paseo Highlands Park) to get some fresh air and do some reading. I noticed a unusual cloud cover and a rainbowish looking reflection in the sky. I captured a couple photos to show my wife the amazing sky this evening in Phoenix. After viewing the first picture I noticed an object in the picture that I could not see with my eyes, so I took a couple more. The UFO started moving higher out of sight after a few minutes. I did not alert anyone in the park because the object moved out of sight and was not visible with the eyes.