I was driving home heading north on hwy 145 when i noticed 3 lights in the sky. They were flying fairly low and would go north to south first,then east to west. Idrove for another four miles to my home and the lights were still in the sky. They were flying as if they were searching for something,but as i stood in the back yard they started to fly not from north,south then east,west but in a large circular area.As they flew in this pattern i noticed they were regular aircraft but had two bright white lights on them like headlights. By now my mother had gotten out of bed to see why i had not came inside. as she was leaning out the back door i showed her what i was watching. Then out of nowhere came this huge object. It was approx. 300ft. wide and 175-200ft. long. It was completely dark, no lights,or sound,and was flying very low' around 250ft. It headed north rather slowly and i could hear the air coming off of it .As it went to the north it then slowly turned to the east and drifted out of sight. Then the other aircraft took off in the same direction. I wanted to see if i could spot it again but it had shaken my mother to the point she wanted me to come inside.I have never seen anything like it since and will never forget it.