Aircraft with unusual lights, triangular shape with 5 circular lights on the bottom, heading west.

I looked up and saw what at first was a bright light that appeared to be hovering. I was heading north at about 20 mi. per hour and slowed as the object oddly was getting closer and I could see far more detail. It was triangular and had five circular lights beneath. One light in the point of the triangle, 2 lights toward the center, and 3 lights at the bottom. I have never seen a plane with a configuration like that….nor a clearly triangular aircraft (resembled a stealth warplane, but larger. In my vision the aircraft seemed oddly to be moving very slow….then suddenly accelerated at an unusual rate of speed….over my head going west. I tried to stop and recapture vision, but it was gone