Single bright white light observed in eastern sky of northern hemisphere moving from south to north approx. 40-45 degrees off horizon.While Moon gazing observed a single bright white light moving in a straight line from south to north in the eastern sky, approx 40-45 degrees off the horizon. Observed light with naked eye for approx 5 secs, then with pair of small 8x power field binoculars for approx 10 more secs. Observed light for approx 5 more secs with naked eye and then light simply vanished as it neared the constellation Cassiopeia. No flashing lights, such as strobe or navigation lights were observed at any time, nor any high altitude contrails associated with engine exhaust. No sound emitted from the light nor were any aircraft observed in the area. After light vanished, monitored sky for approx. 10 minutes for light to reappear with negative results. Conditions were clear sky with almost full moon. Monitored sky the following night (07/21) from 2200 - 2230 hours to see if light would reappear. Effort resulted in negative results. Have 26 years experience with military (Air Force) and very familiar with aircraft operations. Also have amateur experience skywatching satellites in orbit. This object was far too bright to be a satellite. My vision has been tested at 20/20. The single most important factor that drew my attention to this sighting was the brightness of the light.((FOLLOW-UP CORRESPONDENCE WITH WITNESS))Dear Mr. ((name deleted)),Thank you very much for the excellent report! Your credentials with the USAF appear to speak for themselves.One of the tests as to whether the object might have been a satellite is the amount of the sky the object traversed in the time you were looking at it. Can you estimate the angle it covered, measured in degrees, it covered during the 20 seconds you watched it?Thank you again for sharing the information with our Center!Cordially, Peter Davenport((RESPONSE))Yes, I would estimate the light travelled approx 55 degrees. I base this estimate by using my arms as a reference; by facing due east and stretching out my arms to point due north and south, the distance between my outstretched arms would be equal to approx 180 degrees. I first viewed the object about 20 degrees to the right of my head and then tracked it to a point about 35 degrees to the left of my head when the light vanished. ((name deleted))((END))