The famous Northern and Southern Lights — Aurora Borealis and Aurora Australis for those Latin lovers among us — are caused by high-energy particles from the Sun cascading down on Earth. As they near our planet, they interact with Earth’s magnetic field, which channels them toward the north and south magnetic poles.
There they are accelerated downward, and at altitudes ranging from 90 to 700 km (50 to 450 miles), the particles collide with atoms of our upper atmosphere, a process that results in a glowing field of excited gas. These sheets of lights can take on many beautiful colors, and often persist for hours on end, dancing gracefully in the polar skies.
Earth isn’t the only planet that experiences aurorae; recent images from the Galileo probe, in orbit around Jupiter, clearly show massive auroral displays many times the size of Earth taking place high in the Jovian atmosphere. As we study our fellow planets in ever-increasing detail, it is all but certain that more such spectacular and eerily beautiful scenes will be discovered.