Silent,bright intermittent WHITE light - on /off but not strobing- white light on object moving from west to east @~10,000 ft

3:40 am, looking west northwest notice intermittent bright white on object at aporoximately 10,000 ft altitude ( we constantly get a lot of Ohare airport traffic overhead here in the Chicagoland area and become a pretty good judge of plane altitudes
having seen them in all phases of approach and take off all my life and have flown extensively myself to Europe and Asia and Pacific)
moving from west to east in a path that would've taken it right over the south portion of Ohare airport field.
Silent with intermittent on/off bright white light that would move from side to side of object during off period.
No port or starboard red or green lights, no under belly red light either.
I could not discern a shape only intetmittent foreward facing very bright intermittent White light shifting from side side as it moved across the sky in about one minute or less time.
If it was military it had no red or green lights but was being obvious about its presence - strange that it was not constant white light but instead on/off ftom side to side.