Cluster of orange/red pulsating lights vicinity of Philadelphia AirportFrom our back porch, through a clear, unobstructed opening in the trees that faces north northeast I saw a tight cluster of approximately 50 or more (difficult to count) blinking orange to reddish lights. They were in a loose cluster formation traveling east to west, much slower than an airplane and without any sound. The sky was clear to the north with high, thin clouds coming in from the south. The lights were below the clouds but appeared very high. There were also lights from a plane traveling north, above the clouds and above the cluster, but from my viewpoint ‘through’ the cluster. The wind was light and the direction the lights were moving seemed to contradict the wind and the cloud movement. I know winds can vary with altitude, and I do not know how high these lights were flying. Having seen a fireball recently, I stopped to consider what I was seeing and realized it was not fireball, fireworks or anything else that I’d ever seen before. I watched th! em for several seconds, thinking they would quickly vanish, and when they didn’t, I called my wife and asked her to bring the camera. There is over 5 minutes of video that document most of what we saw. What they looked like to me were electrically generated lights, not flame, pulsing from a very bright orange to a not so bright red and back again. No way was it flame! They pulsed at about 1 second intervals, not in unison. The lights were moving at about the same speed and direction with some slight variation. There seemed to be two types – one type was definitely brighter than the other type. I went inside to get the phone to call our neighbor but stopped, grabbed my binoculars instead and returned when my wife said the lights were disappearing. The way they were disappearing was just to kind of fade out. No loss in altitude. Each one just fizzling out where it stood, bunches at a time until the only ones that were left were a handful of the brighter ones. As those last ones diminished, a few more of the brighter type drifted into view from the east. The position of our house and a large holly tree prevented us from seeing where they originated, they just drifted into our small field of view and every single one of them vanished within our sight after crossing our small field of view. A couple at a time, then one at a time, with longer spaces in between, and then they were done. The last one seemed to change direction after crossing the opening in the sky. It seemed to move further away to the north before vanishing. When I tried looking at them with my binoculars and it appeared that the orange light was coming from the bottom of the object and the red light was coming from the top. It also appeared that they went a little faster when the red light was glowing, and slower when the orange light was glowing, though that could have been an illusion. I’d like to think this could be explained as being Chinese lanterns or something of the sort, but the intensity of the electric light, their height, the fact that they remained in a such tight formation, and that they vanished so simultaneously, make it difficult to explain. I’ve lived my entire 50+ years under the flight path of Philadelphia International Airport. I’ve worked outdoors all my life. I intentionally spend a lot of my leisure time looking at the sky, day and night, and enjoying the variety of light displays, natural and manmade. This is a very urban area and it’s not uncommon to see distant fireworks or balloons from a party. What I saw on this date was something I’ve never seen before – and I’m just amazed.