huge triangular craft floating in the night sky moving in a circular direction before heading in a northern direction.

sometime in the summer of 1985 me, my brother, and a friend were outside playing catch on our street and it was around 8 pm when we noticed a huge triangular object gliding slowly through the night sky it had lights on each point of the triangle but you could see the dark silhouette of the object to make a conclusion that it was not three separate objects. my friend ran to go get his camera but forgot to his flash so we were unable to get it on camera.  It was moving very slowly and at one point was literally above us!! it moved in a circular direction over and past the mountains and then came around and headed north.  I decided to write my ufo encounter because i have read similar stories about this huge object.  Many report seeing small crafts flying around and speeding off but this object that i saw was VERY big.  and another thing i forgot to mention is that it made NO SOUND!! This encounter happened 15 years ago but it still puzzles me to this day.  What was it?  if anybody has had a similar encounter with this giant craft please email and let me know.