My wife and I were sitting at ground level on the back steps of a beach house in Nags Head, when we observed the aura of a pulsing green light over the ocean horizon, about seven miles distant. The apparent size of the aura at that distance was about an inch across. The light moved from the south extreme horizon to the north extreme horizon within five seconds. It then reversed direction and moved south to the extreme horizon at the same speed. It then re-centered and vanished. There was no sound.