Extremely bright light blinking on then off and moved to different position in high atmosphere

While parked on the side of the highway making a call, I observed a bright light suddenly appear high in the dark sky almost 80 degrees from the horizon. It came on instantly and was very large, especially with no landmarks or other objects in which to give it reference. It blinked off and then re-appeared about five hand-widths further east in the sky. Either the object moved extremely fast from that original position after it darkened, it teleported or there was another object that became visible. There were no sounds, no trails, no other colors except bright white, almost like a bright white LED bulb turning on and then off. I couldn't discern a shape; just the luminance. It wasn't the reflection from passing cars (as I wasn't looking through glass) or from an aircraft that I know of or have seen before. I can't emphasize the size and brightness enough. Very unusual.