"By exploring a larger space such as Jupiter, we can better understand the fundamental physics governing Earth's magnetosphere and thereby improve our space weather forecasting," said Peter Delamere, a professor at the UAF Geophysical Institute and the UAF College of Natural Science and Mathematics.

"We are one big space weather event from losing communication satellites, our power grid assets, or both," he said.

Space weather involves disturbances in Earth's magnetosphere caused by solar wind interactions with Earth's magnetic field, often resulting in power and communication disruptions. Delamere, along with co-authors from UAF, detailed these findings in a recent AGU Advances paper.

Delamere's team, using data from NASA's Juno spacecraft, indicates Jupiter possesses a complex magnetosphere with both closed and crescent-shaped open magnetic field lines at its poles, a topic of scientific debate for over four decades. These open lines allow direct interactions between the solar wind and Jupiter's ionosphere and atmosphere, differing significantly from Earth's magnetospheric dynamics.

"An open magnetosphere refers to a planet having some open-ended magnetic field lines near its poles. These are previously closed lines that have been broken apart by the solar wind and left to extend into space without re-entering the planet," explained Delamere.

This interaction does not produce auroras, which occur on closed magnetic field lines, but it does transfer solar wind energy and momentum into the planet's atmosphere.

Delamere's research, sparked by data unavailable before the Juno mission, supports previous models that predicted open magnetic fields at Jupiter's poles. These findings were also reinforced by a 2021 study suggesting two regions of open magnetic field lines at Jupiter's poles, co-authored by Delamere and Binzheng Zhang of the University of Hong Kong.

"The Zhang result provided a plausible explanation for the open field line regions," Delamere commented. "And this year we provided the compelling evidence in the Juno data to support the model result. It is a major validation of the Zhang paper," he added.

According to Delamere, understanding Jupiter's magnetosphere is crucial for grasping the broader principles of magnetospheric physics, which vary significantly between planets like Jupiter and Earth.

The new evidence from Juno shows polar ion flows in directions opposite to Jupiter's rotation, aligning with the open field lines model. Delamere concludes, "The polar location of open magnetic field lines may represent a characteristic feature of rotating giant magnetospheres for future exploration."

This research will be further discussed by Delamere at the upcoming Conference on Magnetospheres of the Outer Planets at the University of Minnesota.

Research Report:Signatures of Open Magnetic Flux in Jupiter's Dawnside Magnetotail

Research Report:How Jupiter's unusual magnetospheric topology structures its aurora

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