giant ball of fire seen over tucson hour after dark around 1989

I don't know the day or month. it was about an hour into the first movie, which would be about an hour after dark. me & two friends were at the Apache drive in theatre , facing the west screen looking west. as we were watching the movie all of a sudden the entire area lite up almost like daylite but not that bright. I assumed that a jet from the airport was making a turn and it's headlights was shinning on us, so I didn't  turn to look at it , because i didn't want to be blinded by it's light. after a couple of seconds & the light didn't go away I turned to see why, just as I did  it came in view. it looked like a giant round sphere of fire. It was approxamatly 1000 to 2000 feet in elivation, one half mile south of us, it only took 2 seconds to travel from our local to the top of the south end of the tucson mountains, which it just bearly cleared. It was at least as big or bigger than the U of A football stadium , which seats 50,000 people. it was totaly silent & there was no sonic boom or exhaust trail. being only about an hour after dark in the tucson area, there must have been at least 100,000 people outside , not facing north who couldn't possibly have not seen it.  for the next two days I monitered the tv news, radio news & newspaper looking for reports, but saw none whatsoever. I researched ball lighting & found it couldn't be that. nothing in science explained what it could have been .   a year or two later the same phenomenon was reported over southern california, heading from southwest to the northeast toword  area 51. the one i saw was heading basically east to west slightly southeast to northwest.  a couple of years later I was watching a taped video lecture of a young german scientist giving a lecture about WWII Nazi UFO technology & in it he spoke about a perticular sphereicle  craft  that would give the apperance of a giant ball of fire. that was the only thing i have ever heard that sounds like an explanation for what  me & my friends saw. . thank you.
Witness indicates that the date of the sighting is approximate.  PD