I was outside standing on my front porch smoking a cigarette when I heard an incoming aircraft flying in the direction of local air terminal, about 3.5 miles from my location. I looked up in the sky to look for the craft, and saw the plane a few moments before it passed behind a cloud formation. An instant later, I noticed a white orb coasting along the same adjacent trajectory as the plane, an estimated 200-300 yards south of the airplane. I observed this white orb for several seconds, then lost sight of it for three or four seconds as it passed through another cloud formation. The orb emerged from behind the cloud formation, where it remained visible for not more than another seven or eight seconds, before it disappeared behind another cloud and beyond my scope of vision, subsequently. It traveled at a steady speed, effortlessly, from the northeast to the southwest. This sighting lasted about 16 seconds. I raised my voice and asked if anyone else could see it, to no reply. This object did not resemble anything of Earthly origin. I was stunned about what I had observed but did not report what I had seen to the authorities for fear of ridicule. In the intervening period since the sighting, I felt my sense of responsibility and obligation grew, increasingly, to report what I observed, and am first doing so here.