Round, silent, stationary ball motionless in NW sky disappearing when approached by jet fighters.While waiting for my husband to come home from work I went out to look at the stars. We do this frequently. We live at the base of Mr. Graham where the Large Binocular Telescope and the Vatican Telescope are. When I looked to the NW I saw a yellow ball. It was almost over head and I could tell it was not a star. It was motionless & silent As I I continued to watch it I could hear aircraft approaching. They were coming from the direction of Phoenix (possibly Luke AFB). I saw two, what appeared to be jet fighters, approach the object. Then the object disappeared just as if a light switch had been turned off. The jets turned around and went back the direction they came from. I was shocked! I have been a registered nurse for 25yrs and thought I had seen everything. I know I should have reported this sooner but I felt sort of wierd about it as I was the only one I knew of to see it. It really shook me up.