soundless rectangle Trenton Missouri

1981 Trenton Missouri approximately 7:30 pm-8:30 pm I do not recall the date but it was a weekday, a perfect day no need for a jacket but not overly warm.  Clear skies with a slight breeze.  I walked out of our house to go for a walk after dinner, on the front porch I stopped and looked up and there not terribly high above me was a rectangle shaped object of substantial size.
It looked like a 9 domino with a pattern of 5 dots of light on one end and 4 on the other, the lights were white and red and did not blink.  The object appeared to be rectangular but I do not recall actually seeing edges only the impression of them.  The object made no sound, and did not move.  It appeared to be perhaps 75-100 yards above me and slightly in front of me so that the leading edge was not quite over my house.
I stared at this object for approximately 5-10 min and put my hand on the door knob to go get my parents ( I was a teenager at the time) when the door opened behind me.  I turned away from the object and saw my mother opening the door and I said "mom look at that" and turned to direct her attention to the object and it was gone.  Also she was coming to look for me because I had been outside for a little over an hour and it was dark and too late to be out.  She did not see the object at all, but later she mentioned that a police officer had reported a similar object as had a few others that night so if their reports were documented the exact date should be easy to determine.
The date and even the fact of spring or fall is uncertain to me 31 years later, but I do recall very clearly that it was a beautiful clear comfortable day with a slight breeze and clear skies and what this object looked like and how I felt.  There was no fear, only curiosity and interest.  Also I know that I was not standing on that porch for an hour looking at the sky, only a few min.  How the time difference is accounted for I have no theory.
Witness indicates that the date of the sighting is approximate.  PD