Have We Figured Out Jupiter’s Northern Lights?

The short answer: Yeah, we think so!

NASA, ESA, J. Nichols, G. Bacon (STScI), A. Simon (GSFC) and the OPAL team. Nichols is one of my lecturers, so I’m kinda biased 🙂

To bring everyone up to speed: Jupiter, alike Earth, experiences an aurora borealis around its north and south pole. These lights are icy blue or pink in our images, but they’re actually only seen in the X-ray.

You would be correct in saying that Jupiter’s lights work like ours; charged particles zoom into Jupiter’s atmosphere and collide into the gas particles that make up the atmosphere. However, one thing we didn’t know until now is the origin of the charged particles.

The Key is Jupiter’s Magnetic Field!

Jupiter’s magnetic field rotates with the planet. So as the solar wind hits the field, it heats the particles trapped in Jupiter’s magnetic field and also makes them oscillate along the field lines. This is a complex process called electromagnetic ion cyclotron waves (EMIC waves), and is backed by the fact that the X-ray Aurora are in sync with the oscillations in the magnetic field.

It’s these heated particles that go on to make the aroura borealis, but where did these trapped particles come from?

spacecraft: ESA/ATG medialab; Jupiter: NASA/ESA/J. Nichols (University of Leicester); Ganymede: NASA/JPL; Io: NASA/JPL/University of Arizona; Callisto and Europa: NASA/JPL/DLR

Jupiter’s aurorae happen all the time (usually every 27 minutes) so it needs a constant supply of particles. Scientists have confirmed these particles to be mainly oxygen and sulphur, which are supplied by astronomer’s beloved moon Io! This moon is one of the most volcanic celestial bodies in our solar system, and provides a constant supply of gases.

So, Io supplies Oxygen and Sulphur which get trapped by Jupiter’s magnetic field. Solar wind creates EMIC waves, and send the particles down to the poles. These particles collide and create the X-ray aurorae!

The scientists we have to thank for this amazing discovery are Zhonghua Yao and their colleagues from the Chinese Academy of Sciences who realised the synchronisation between the magnetic field and the aurorae, and Dr William Dunn from UCL for co-leading the research. You can find the paper they published along with many other researchers here.

Another day, another win for Astrophysics!

Credit: NASA, ESA & John T. Clarke (Univ. of Michigan)

One comment

  1. I remember reading a while back that Jupiter’s aurora are synced up somehow with Io’s orbit. I don’t remember the details, but I know it was hypothesized that sulfur from Io must be contributing to the aurora somehow. I always thought that was a really neat-if-true hypothesis. Cool to see we have some confirmation now!

    Liked by 1 person

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