Diamond-shaped object with lights seen flying over Interstate 83.

I was on my way home from work at 8:48 p.m. As I pulled up in front of my house (just outside of inner city York), I noticed something in the sky moving out from behind the trees near my yard. I looked up and spotted a large, irregularly-shaped diamond-like object travelling at a high rate of speed overhead. By my estimations, the object was flying at an altitude of 8,000-10,000 feet, and was between roughly 100 and 120 feet in length, though this was hard to determine as it was dark outside and I could only vaguely discern the sides of the object. There were 3 solid yellow lights on its points, and a blinking white light in its center. It was completely silent as it passed. It was heading northeast over Interstate 83, and disappeared from my field of vision after about 1 minute.