Metallic flying saucer over Arlington on May 2017

On May 10, 2017, a man named Joe was with his family in Arlington, Virginia. Without knowing it, he caught a picture of a metallic flying saucer

Witness statement:

I discovered the object in a picture about a week later, but thought nothing of it until someone else saw it and then drew some question as to what it is/was. it was taken at the marine corps memorial in arlington va during police week in 2017. there were very few people in the immediate area. there were no balloons, no drones, no frisbee playing no airplanes/helicopters etc in this area that would explain the shape of the object pictured.

PS: my wife and 3 kids were with me when this pic was taken, they can all corroborate the fact that the pic i have is not doctored, manufactured, manipulated, staged etc.

Source, 25th December 2018