Sci-Friday: New research uncovers new details of Jupiter’s out of this world auroras
FAIRBANKS, Alaska (KTVF) - While spring has arrived and aurora sightings become fewer here on Earth, for this week’s Sci-Friday we set our sights on Jupiter and the unusual aurora that’s caught the eye of scientists around the world.
An international team of researchers have made a key discovery related to the alien aurora that can be found in the skies over the giant planet.
Peter Delamere, Professor of Space Physics at the University of Alaska Fairbanks and co-author of a recent paper revealing these findings explained the research. “Through the 90s of course we started getting images of the aurora from the Hubble space telescope, and what we realized is Jupiter’s aurora is very different from Earth. It’s up on the pole, it’s in a circle, but it’s not just a ring. The whole region is filled with auroral emissions.”
This is unusual compared to Earth, as on our planet the aurora appears around an area referred to as the auroral oval - a high latitude region around, but not at the magnetic pole. Jupiter’s polar region, however, is dense with auroral activity. Delamere said, “What’s interesting about Earth is that when you go poleward of the auroral oval, the magnetic field lines don’t close back on themselves. They simply map out into the interplanetary space. We call those open field lines - this is what we call magnetic field topology - so open field lines generally don’t have aurora and closed field lines can have aurora.”
Using data from NASA’s Juno space probe, Delamere and the rest of the research team used computer modeling to discover how Jupiter could have aurora in this region of its magnetosphere that should consist of open field lines.
“We thought Jupiter must be like Earth, all the magnetic field lines coming out of the pole must be open. But it’s puzzling because how do you generate an aurora on these open field lines? Well it turns out that this model that we ran showed, in fact, that these magnetic field lines are closed in the polar region. So if you start in one hemisphere they map and take you all the way down to the other hemisphere - and this is completely different form Earth. This model it shows that there is closed flux, but there’s also a little crescent of open flux within the system,” said Delamere.
This discovery reveals that Jupiter possesses a mix of open and closed magnetic field lines in its polar caps. According to Delamere this is a major paradigm shift for the way that we understand magnetospheres.
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