Mystery solved: Jupiter’s X-ray aurora explained

X-ray flares triggered by vibrations in magnetic field lines.

Two side-by-side images of Jupiter one showing an aurora at the south pole, the other at the north.
Overlaid images of Jupiter's pole from NASA's satellite Juno and NASA's Chandra X-ray telescope. Left shows a projection of Jupiter's Northern X-ray aurora (purple) overlaid on a visible Junocam image of the North Pole. Right shows the Southern counterpart. Credit: NASA Chandra/Juno Wolk/Dunn