I was sitting on my balcony relaxing, i normally view helicopters fly by every once in a while, from the tourist helicopters to police/military helicopters... this night as i was sitting on my balcony, i noticed a black rectangular object hovering above the horizon with blinking illuminating lights on each corner of the black rectangular object. the blinking lights seemed to be pulsating sequence, almost like a heart pulse. the object hovered for a moment, then began to from sw to w slowly, too slow to be an airplane. the object then stopped for a few seconds, go backwards slowly, stopped again, and then moved w until it went passed my line of sight. throughout the entire time the white pulsating lights on each corner, continued to pulsate the entire time.I have attended many air shows, i have seen many military aircraft, my uncle served in the military, and i am a aviation and military aviation enthusiast. i have never seen anything like this in my life!