Orange Triangular Light Formation southeast MI

Today, July 31, 2013 at approximately 11:20 Grace Olsen and Patrick Micallef saw three orange glowing lights in triangle formation slowly moved across the sky in uniform shape, but growing in distance equally. Sky was dark but cloudy; no stars were visible. There was no sound coming from the orange glowing lights. Also, no other aircraft was visible from our standing positions. Losing the lights behind a tree, We then walked around the block to attempt a better view, but then lost sight of the lights.