Possible metalic object reflected sun's light very brightly for over an hour.Very large bright object North West evening sky, brighter and larger than any planet, was approached by a jet aircraft and after dark by another aircraft. Brightness diminished with setting sun, but remained stationary for at least an hour as we watched. There were no stars in the sky when we first saw it, and the thin crescent of the moon was visible. The sun reflected off this object, which I emphasize, remained stationary until it was no longer visible in the night sky. My companion watched it after dark thru binoculars and describes it as looking like a jelly fish.