Bright red light traveled across sky in Tucson, Arizona. No sound, then flickers out to the west of city.I was in my back yard on the 8th of Feb. 2017. I do amature astronomy and am outside many nights. I saw what I thought was an airplane at first coming from the south east. As it came closer I noticed it had no blinking lights. It was just one very bright red light. It was so different than anything I have ever seen that I called for my wife to come out to see what she thought. She was also puzzled as to what it could be. It proceeded to fly overhead just south of our location and toward the west. While it was in the western sky at about 40 degrees over the horizon the light sputtered off and on about 4 times, in about an 8 to 10 seconds period then went completely out. There was no sound coming from the light and the sly was clear, no clouds and an almost full moon. I would very much like to know what could cause such a light. I have ruled out stars, airplanes, helicopters, satellites, space station and satellite flares. Even ruled out a rocket since I don't! believe rocket launches go over Tucson. It traveled several miles across the sky so it was not a civilian drone. Could it have been a military drone? I have no idea what it was.