Auroras paint the sky around the poles when the sun is particularly active, flinging highly charged particles at Earth’s atmosphere. Scientists once thought that the gorgeous events were mirror images, but to their surprise, displays at the north (the aurora borealis) and south (the aurora australis) don’t precisely match.
Ever since scientists realized these two celestial displays don’t line up, they’ve been trying to sort out why. Now, a team of researchers thinks it has found the reason — asymmetry in Earth’s magnetic tail. But what’s stranger is that the asymmetry is caused by the precise inverse of what scientists expected.
“The reason this is exciting is that earlier we have thought that the asymmetry in the system enters the magnetosphere by a mechanism called tail reconnection,” Anders Ohma, a doctoral candidate at the University of Bergen in Norway and lead author on the new study, said in a statement released by the journal. “What this paper shows is that it’s possible that it is actually the opposite.”