Jupiter is a stunning planet in many ways, with its beautiful bands of clouds, the largest storm in the solar system, and unusual phenomena like geometric storms at its poles. And it has some further oddities we’re still learning about, such as the fact it has strange X-rays auroras somewhat comparable to the northern lights here on Earth.
For 40 years, scientists have wondered how these X-ray auroras work, and now a new study reveals the mechanism behind them. Like the auroras on Earth, Jupiter’s auroras are caused by electrically charged particles interacting with the planet’s atmosphere. On our planet, these interactions make beautiful colors in the sky when they interact with the lines of Earth’s magnetic field, which appear as auroras near the magnetic poles. But on Jupiter, the auroras appear in different areas and are different between the north and south poles. Sometimes they even pulsate, which suggests they are due to a different kind of magnetic field.
Artist’s impression of the upcoming Jupiter Icy Moons Explorer mission in orbit around Jupiter. 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
Using computer modeling, researchers were able to show that while Earth’s auroras are created along what are called open field lines, which start at Earth and reach out into space, Jupiter’s auroras are linked to closed field lines, which start inside the planet and then stretch out for thousands of miles before ending back in the planet again.
They also found that the pulses in the auroras were due to fluctuations in the planet’s magnetic field, caused by the planet’s rotation. The electrically charged particles “surf” along the field lines and eventually hit Jupiter’s atmosphere, causing the aurora effect.
This phenomenon was observed used data from the Juno probe, which took continuous readings using its XMM-Newton X-ray instrument for 26 hours in 2017. The researchers were able to see a relationship between the planet’s magnetic processes and the production of the X-ray auroras.
And this might not only happen on Jupiter. A similar process could happen in other places in our solar system, or even beyond.
“This is a fundamental process that’s applicable to Saturn, Uranus, Neptune, and probably exoplanets as well,” said lead author Zhonghua Yao of the Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing.
The research is published in the journal Science Advances.