I was standing in my yard star gazing which i do quite often. i noticed a star move very fast and stop next to another one that was there already. then two more appeared stationary at first, then these two were flashing off and on, and darting in a straight line foreward, then backwards. then all four sort of lined themselves up in some kind of geometric shape, after they moved within equal distance of each other, they disappeared. "poff" gone. this went on for about ten minute, the sky was crystal clear. thanks.