Auroras start at a distance of 80-200 km above the Earth's surface.
The color of the aurora will be blue/purple if the air molecules in the area below 120 km are excited.
If the air molecules in the area from 120-180 km are the ones that gets excited the colour will be yellow/green.
Above 180 km gives the red light in the aurora.
The most powerful aurora ...
If your eyes are fully adapted to the darkness you will be able to see a persons face in the light from the auroras.
By fully adapted to darkness means sitting in a totally dark room for 20+ minutes before you start looking at the night sky. The time you will need to adapt depends on your age.
Any bright light will destroy your night vision. As we get ...