Strange blue pulsing light

I was standing outside in my backyard smoking a cigarette when I happened to see a blue light in the sky.  Upon closer inspection of this light I had noticed that the light was pulsing, instead of just blinking like a normal aircraft.  For the first few seconds it was moving rather slow and in my direction, then the light did a complete 180 (which appeared to defy the laws of physics) and sped off into the distant clouds.  I thought it was rather strange, I've seen nothing like that before.  I can not say that I believe it was extra-terrestrial, though a possibility,  I just thought it was strange.