Formation of lights in a < shape that where visible for several minutes and then suddenly disappeared.Commerical airliners fly quite frequently into Harrisburg International Airport so the pattern was in the general vacinity. As I watched one plane heading south to north I notice a formation of 4-5 lights flying north to south. The altitude was higher then the commerical airlines fly if their about to land or have taken off and yet the lights where as bright as if much lower. The sky was extremely clear as I live in the country. This formation flew silently until it reached the Orion constellation at which point as it was crossing it (from my vantage point) the formation disappeared. I stood there for 5-10 minutes looking for any tail lights of planes in that area and saw nothing. I saw a plane in the north and a small craft far south east but nothing of the formation. Unfortunately I was by myself and had no witnesses. I spend a lot of time looking at the stars on winter nights and this was very unusual.