Sitting on my patio late afternoon on cloudless day. heard the sound of single engine aircraft and looked up and observed it at approx 1000 to 1500 feet heading south-east. then caught sight of another object passing under the flight path of the aircraft. it was heading north to south at a much higher speed. it appeared to be smaller than the aircraft and round in shape, (orb). it had no wings or tail and the surface was very reflective of the late afternoon sun. in relation to the airplane it was traveling at a much higher speed without any sound that could be associated to it. it flew in a straight line without any deviation until my view was blocked by the roof of my house.