White beacon of rotating white light followed by the same in green

Six of us from Chanute AFB were in a car in a cornfield about 8 miles North of Rantoul IL (near Paxton).  We were sitting there parked along the side of a dirt road when there was a terrific white light that flashed at us like a rotating beacon at an airport.  A green beacon type light immediately followed this.  (Chanute AFB's runway was closed since the 1960's and the nearest Airport was many miles away)  The eerie thing about the incident is there was absolutely no noise.  If this was an aircraft with lights that bright we should have heard noise, felt vibration or something.  I thought I had imagined the lights when a guy in the back seat said, "did you see that"?  I do not remember the names of the people in the car other than they were people stationed at the base.  I know this is not much to go on but the incident stayed in my mind for many months after it happened.  Recent stories I have seen on cable reminded me of that evening.
Date is approximate.  We would welcome reports from other witnesses.  PD