It was around 10:15 Tuesday night, July 12th. There were two adults plus children present at the time. It was a very clear note as you could see more stars then normal for are area only living miles from downtown Pittsburgh. Before we told the children to go inside we were all on are back deck with a perfect view of the sky. My girlfriend had told mentioned how clear it was so we all looked up into the sky. Within seconds we all seen what we had thought to be a shooting star, which then proceeded to act odd. It was a bright light with a trail that stopped in mid air and began to change direction was flying dead east then banked south east. The light would brighten then slowly dim out and slowly glided out into the horizen which is a tree line. No more then two minutes later, after getting the frazzled kids inside, another object looked like it was on its trail only this craft had 3 lights and had a shape of a triangle and made no noise what so ever. As it flew over us the front light disappeared and it also went of into the horizen. Approximately 3 minutes later, u could hear the loud roar of a military helicopter chasing after both crafts going in the same direction. After the helicopter was out of view the original ball of light returned. Slowly moving across the sky getting brighter and then dimming out moving in very odd directions then out of nowhere disappearing again. The sky at this time was full of blinking lights from aircrafts which looked like they were flying in grid patterns all across the sky. Everywhere you looked thats all that could be seen. 20 minutes into this a very bright light emerged from out of the tree line from the south west from the direction of our airport/ air force base. This aircraft mad obsolutly no noise and was very large and was shaped like a stealth bomber it banked and flew to the north. No more then 5 minutes later another air craft which looked and sounded the same came from the southwest only this time it went north east. 5 minutes later the ball of! light r eturned in the form of a bright flash. Other aircraft littered the sky and were flying at a high altitude. The ball of light was flying very close to these aircrafts which were in close formations around the object. It would fly in between them then very fast spin around them and gain distance. Then once again disappearing instantly. We never seen the ball of light again for the next couple hours which we observed the sky but the sky was still VERY active with other aircraft. This all took place until 12:45 wish when we went back inside.