Saw a multi-colored, rectangular object flying through the sky from the NE to the SW...

September 4, 1980, approx. 17:30: The sun was still up, but setting in the west. While talking to a neighbor in the front yard, I had a strange urge to look at the sky. From the NE, a odd, multi-colored, box-rectangular object was silently zipping through the sky to the SW. If on the ground,its dimensions seemed to be about 30' by 30'. It appeared to be constructed like a box-kite, with glowing, colored spars, as if they were fluorescent tubes seen on a carnival ride. Green, red, amber, violet, were the colors. The object rotated end-over-end as it flew. It was at a height around 5,000 ft., and was moving at very high speed. I would guess the speed was around Mach 2 or 3, since it travelled from horizon to horizon at that altitude in less than 15 seconds, and disappeared behind a stand of Southern Oaks, from my perspective. There was a peculiarity about the event that I won't forget: I sensed intuitively that the "craft" was under highly intelligent control, and was a "probe" sent for reconnaisance purposes by someone or something not of this Earth. (Weird, huh?)