Why the Northern and Southern Lights Look Different
For the past 10 years, something has been befuddling scientists and world explorers: why auroras look different on the South Pole than the North Pole.
The auroras are caused by solar wind. Basically, Earth has a magnetosphere around it. You can think of this as a protective shield. When solar winds (which carry charged particles and plasma) move through space and come in contact with Earth’s magnetosphere, they are funneled into “field lines” that run between the north and south poles. According to Motherboard, “The precipitation and ionization of these particles prompts atmospheric molecules to emit the colorful lights often seen in polar night skies.” Those lights are what we call the auroras.
Scientists have long believed that the light displays on the North and South Poles were mirrors of each other. It made sense if the world was perfectly round and the magnetosphere around it was, as well.
But in 2009, scientists discovered this was not so. The light displays appear in different shapes, depending on which pole you’re at.
Earlier this week, scientists suggested a reason that could be behind the asymmetry between poles. The team behind the study discovered that when solar winds hit the daytime Earth in an east-west rotation, the twist of the auroras becomes asymmetric. Scientists believe this asymmetry could be behind the different patterns seen at the two poles.
Here’s a video explainer if you’re more of a visual learner:
But this study has a much more far-reaching impact than simply understanding a bit more about the auroras. Understanding the asymmetries will help scientists “accurately predict the location and timing of geospace phenomena,” Nikolai Østgaard, lead author of the study, said in a statement.
“This result is kind of a big deal,” said Mike Liemohn, the editor-in-chief of The Journal of Geophysical Research: Space Physics, where study was published.
Now that we know a little more about the phenomenon, it’s time to get out there and see the lights for yourself.