I found it odd that there were no anti-collision lights nor position lights, and made no sound at all.About an hour before actual sighting, there were 2 aircraft with full position lights and anti-collision and landing lights on. One appeared to be chasing the other for about a hour. I didn't hear any aircraft sound and they were rapidly changing direction, so that was kind of unusual in itself. I decided to stay outside and watch them when I noticed traveling from the south a triangle shaped aircraft without position lights or anti-collision lights, but what appeared to be landing lights in all 3 corners. I couldn't see the body of this aircraft as it was dark outside. the lights turned and headed east and faded into the darkness. I'm not saying that it is of alien origin, but that it is an unexplained unidentified flying object. I would like to know if some special aircraft was being tested in this area. This is the 1st time seeing something like this.