Was driving home south bound on highway 287 with female companion in the passenger seat. At about 11:45pm she and I notice this orange brown glowing circular object moving at an incredible rate of speed from east to west. It kept the same path, from our location it didn't appear to be angled downward as most meteorites; instead it moved across parallel with the horizon and then vanished. It didn't change size and the light didn't appear to dim.