Two UFOs seen from an airplane over Denver, Colorado

On July 7, 2013, the passenger of an airplane was over Denver, Colorado, when he saw two bright UFO descending together.

Witness report:

I was flying out of Denver International Airport and was taking pictures from my seat when the pilot announced we were flying over the Rocky Mountains. It was not until later that I noticed the two objects in the distance and I didn't remember seeing them when I was taking the picture. The emission trail coming from them seems to show they are flying in the same exact trajectory and descending rapidly. They seem to be flying perpendicular to each other and from a very high altitude. I guess they could just be airplanes but because of these points I thought it was odd. I would just like to get some opinions of the picture.