The Aurora is a natural light display which is created when protons and electrons stream out from the solar surface and slam into the Earth’s magnetic field. As the particles are magnetically charged they move in spirals along the magnetic field lines. The protons go in one direction and the electrons in the other. Those particles in turn hit the atmosphere. Since they follow the magnetic field lines, most of them enter the atmospheric gases in a ring around the magnetic poles. Where the magnetic field lines come together.
The air is made up largely of nitrogen and oxygen atoms, with oxygen becoming a bigger component at the altitudes auroras happen. Starting about 60 miles up and going all the way up to 600 miles. When the charged particles hit them, they gain energy. Eventually they relax, giving up the energy and releasing photons of specific wavelengths. Oxygen atoms emit green and sometimes red light, while nitrogen is more orange or red.
Satellites can take pictures of the aurora from Earth’s orbit. The images they get are pretty amazing. In fact, auroras are bright enough that they show up strongly on the night side of the Earth even if you were looking at them from another planet.