Large, bright, blue/white circular object appeared to do extremely high speed "fly-by" of Earth.

Bright blue-white circular object.  Appeared to be nearly (not quite) same relative size as the full moon appears directly overhead.  Object was above scattered clouds at 6700feet & passed behind them, disappearing momentarily behind the more dense clouds.  Appeared over Alaska Range to Northwest traversed night sky and disappeared over Chugach Mountains to Southeast in two to four seconds.  Land distance from mountain range to mountain range approximately 150 miles.  Alaska range 10,000ft + Chugach Range 5000ft +.  I do not believe object was within earth's atmosphere.  No sound.  No sparks.  No vapor trail.  Object appeared to glow like the flash from an arc welder electrode seen at a distance, but may have been reflection of sun on BRIGHT silver metal.
Date is approximate.  Object was moving to the east, generally, so it probably was not a meteor.  PD