A white "star" in the sky began to spiral and zig zag in the sky then zoomed off and disappeared.

My brother, a friend of ours, and I were lying down stargazing one evening. We were lying in front of my house in the road. Our neighbor is very quiet at night and gets hardly any traffic and is very dark. Great for stargazing. It was anywhere between 11:00 PM and 1:00 AM. Not sure on exactly the date and year. I believe I was around 16 or 17 when this occurred. My brother is three years younger than me. Our friend about the same or two years younger than me. I am 42 now.
 We were all three lying down on our backs and just talking about things in general and looking up a the stars in the sky. The sky was completely clear with no clouds at all. And the sky crisp and dark enough the faint hint of the Milky Way 'clouds' as I call them. No planes were in the vicintiy. Suddenly straight up above us in the sky one of the 'stars' started to move in a slow spiral pattern that gradually got wider. It then suddenly began to zig zag very quickly back and forth in long paths. After doing the zig zag pattern 3 or 4 times it zoomed off and disappeared. We all immediately looked at one another and said. 'Did you see that?' We all confirmed that we did. The object was about the size and brightness of a medium white star. It was large enough to see fine.  The object blended in totally with the other stars in the night sky. It looked just like another star in the sky until it started to do the movements I describe above. There was no sound.The three of us still talk about that night and what we saw whenever we get together.
Date of sighting is approximate.  PD