NASA: It is a rare encounter of two of the most beautiful phenomena on Earth. This is the meeting of sunrise with the northern saddle, over the northeast coast of the American continent.
The video recorded last Thursday its astronaut NASA Barry “Butch” Wilmore, while in orbit over the states of Virginia, Delaware, New Jersey, New York and Massachusettss, on the eastern shores of USA.
Both North and South are most commonly observed along a zone whose center is from the poles of approximately 10 degrees. While just above the poles they appear much thinner.
Its color depends on which gas - oxygen or nitrogen - is produced by the electrons. It also depends on how fast the electrons move.