Violet light seen zig-zagging quickly across night skyI was sitting on my porch smoking a cigarette around 10PM, near Children's Hospital, looking south in the direction of the Mississippi River. I was looking at the sky, when between two houses, I saw a violet/pink light appear. The light was small, appearing as though it was far off in the distance. The light would stay in one location for several seconds, zoom quickly in zig-zag fashion to another location, hover for several seconds, and so on. It would occasionally dart behind a house where I could not see it, but then reappear within view and continue to dart and hover in different spots in the sky. It moved quickly and unsteadily, very much unlike any normal aircraft that I have seen.