“The charged particles energize molecules of gas in our upper atmosphere, called the ionosphere. This causes them to glow. That glow is called the aurora. If it appears over the north pole, it’s called the aurora borealis; over the south pole it is called the aurora australis. Most of the time it glows white or green. However, if the solar storm is fairly energetic, more and different gases are energized and we can see reds and purples in spectacular auroral displays.”
