Reg, green lights, movement atypical.

I was driving along rte 273 towards Newark.  I saw an object with 2 red lights and 2 green lights in the air.  I thought I was seeing an aircraft go down because it moved towards the ground (still high though), stayed there, shot up and down again and then flew forward.  
An airplane and helicopter cannot move like that.  I could not tell the shape as the sky was dark. I thought it was triangular but can't be sure.  I have never seen something like that in my life.