It made no sound and did not travel at speed's of any aircraft I had seen.

There was one triangle shape object moving from from south east to north west.  It was a white light moving in a zig zag pattern, but it never made a turn. It would stop and go backwards (without turning around) at a slight angle about half the distance it had traveled. Then go back at a slight angle about twice as far it had in reverse.  It continued like that until it was out of my sight.  It was summer and my bedroom window was open.  I heard no sound from it. I was roughly 10-12 year's old.