Large Triangle over Austin Texas 1979

In the winter of '79, a friend of mine and I were walking along the campus of The University of Texas in Austin.
It was dark out, being aprox. 9:00 in the evening.
I would estimate around 30 people were also in the area that I could see with folks on both sides of the street we were on.
What got my attention was the whole area lighting up suddenly as if someone had turned on amber colored floodlights that illuminated the street and buildings as if it were suddenly day.
The origin of the light came from above us. There, hovering above the UT Tower was a triangular shaped craft aprox. 100 yards in length with amber colored glowing half-bulbs at each corner underside of the craft. It made no noise and hovered for about 20-30 seconds.
Everyone on the street saw it and we all pointed at it. I was very excited and the feeling I had was one of pure elation.
The object moved silently towards the south and downtown area of Austin and then seemed to accelerate and was out of sight within a fraction of a second.
The next day on the local rock radio station KLBJ, they announced that if anyone had seen anything unusual the night before it was because the Air Force was testing something.
I later became a weather technician for the Texas Air Guard and even though I was already familiar with most military craft I became an expert at recognizing all atmospheric phenomena and different types of aircraft as was required by my job.
I do not believe nor have I ever believed that this huge, silent golden triangle was of a terran origin. I have only found one other witness online to this event who saw it 30 miles to the north of Austin and he stated that he saw several small shapes flying around the triangle as it headed south towards the Austin area.
Witness indicates that date of sighting is approximate.  PD