It can be much more than just a point or ray. One summer I was on an endurance motorcycle ride over the Los Angeles Mountains, altitude about 3500'. As dawn was

It can be much more than just a point or ray. One summer I was on an endurance motorcycle ride over the Los Angeles Mountains, altitude about 3500'. As dawn was about to turn into sunrise the entire sky flashed green. Lasted less than a second. Pretty awesome experience. Terrain in that direction is mostly flat desert once off the mountain.