oval ring of lights hovering, moved vertically and fast

Sitting out on the front porch with a few friends at night.  Looked up at an odd oval formation of lights hovering over the rooftops across the street.  Friends tried saying it must be a blimp or helicopter.  I reminded them that a blimp would not be that low and we would hear a helicopter.  There was no noise and the lights seemed to rotate around the vessel as there was a small gap that kept reappearing at regular intervals.  Within a few minutes the item moved vertically and quickly away.  We wanted to tell someone but figured no one would believe us.  I keep looking ever since for more evidence.  It was a beautiful display.