Lights Flickering in the North Western Sky over Philly/Yeadon AreaI was out in my yard in the evening getting my dog to do her evening ritual when I looked Northwest into the sky and saw some flickering lights. I figured they were airplanes queued up for landing except I realized they were stationary. They were not stars as they were flickering with high level of clarity as opposed to the way one would see a distant star flicker. I noticed two of the lights were in sync so I figured then that maybe it was a tower that I just had never noticed before until other lights started to appear. Some were moving very slowly. Slow enough to be helicopters drifting as they hovered, but there was no sound and then more appeared. Some disappeared and the two that were in sync went out of sync. I noticed a total of about 10 lights. I used my binoculars to see what I could but could only really make out balls of light as it was dark. I did notice that at least one light was reddish while the others were mostly white.I went to get my wife to look and by the time she came out, the lights had gone from about 10 back to 2 and then a few planes came through the area and the lights disappeared.