My wife and I were out walking the dog after dark, around 8pm. Through the trees I saw what appeared to be lights moving across the sky, I first thought it was an aircraft and the branches of the trees were breaking up my view of it. As we topped the hill and the trees were no longer covering the sky we both were frozen in our tracks to witness what we were seeing. The lights (6 of them) were slowly turning on and off in a sequence, one after the other from right to left but the timing was so that one would be starting to glow as the last one was still fading away. First instinct told us this must be an aircraft and the atmosphere was playing tricks on our eyes. Until the sequence started again, from the beginning all the way to the right. At this point I could make out that these lights were on a large mass, which was very dark but seemed to be reflecting some starlight on its top surface (allowing me to make out the vague shape). The object appeared to be several miles away and was well over 500 ft in width. After several sequences the lights stopped and I could still make out the silhouette of the mass, but it seemed to fade away or just left, it was hard to make out. I will say that the area in which it was seen was over a military base that we live near but we have never seen any aircraft of any kind except the occasional helicopter. Whatever this was, it was LARGE, the lights seemed to be signaling something, and it made no sound.My wife and I were both very shaken up by this event. It had a strange vibe to it, maybe not bad but certainly unsettling.