NOT all auroras are created equal. Jupiter鈥檚 light shows aren鈥檛 sparked by the same process that generates Earth鈥檚 flashiest polar auroras, say Barry Mauk at Johns Hopkins University in Maryland and his team, who have been studying data from NASA鈥檚 Juno spacecraft.
Powerful electric fields build up along Earth鈥檚 magnetic field lines, creating wells of electric potential. When electrons from the sun hit these, they accelerate towards the ground. On the way down, they collide with atoms in the upper atmosphere, release energy and emit tiny bursts of light that together create auroras.
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Although Jupiter鈥檚 wells of electric potential can be 30 times as strong as those on Earth, they don鈥檛 align with its auroras. Instead its light shows might come from a process that causes dim auroras on Earth: ripples in the electric field that accelerate electrons less (Nature, ).
Jupiter鈥檚 size means its electric potentials could get so strong they become unstable, turning into waves and random turbulence. This accelerates electrons to produce a dazzling display.
This article appeared in print under the headline 鈥淭urbulence creates Jupiter鈥檚 aurora鈥�