{"id":1357,"date":"2022-02-03T20:28:00","date_gmt":"2022-02-03T20:28:00","guid":{"rendered":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/?p=1357"},"modified":"2025-02-26T13:37:27","modified_gmt":"2025-02-26T13:37:27","slug":"juno-and-hubble-data-reveal-electromagnetic-tug-of-war-lights-up-jupiters-upper-atmosphere","status":"publish","type":"post","link":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/2022\/02\/03\/juno-and-hubble-data-reveal-electromagnetic-tug-of-war-lights-up-jupiters-upper-atmosphere\/","title":{"rendered":"Juno and Hubble data reveal electromagnetic \u2018tug-of-war\u2019 lights up Jupiter\u2019s upper atmosphere"},"content":{"rendered":"\n

New Leicester space research has revealed, for the first time, a complex \u2018tug-of-war\u2019 lights up aurorae in Jupiter\u2019s upper atmosphere, using a combination of data from NASA\u2019s Juno probe and the Hubble Space Telescope.<\/em><\/strong>

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Composite image of two different Hubble observations. The aurorae were photographed during a series of Hubble Space Telescope Imaging Spectrograph far-ultraviolet-light observations taking place as NASA’s Juno spacecraft approaches and enters into orbit around Jupiter. The full-colour disk of Jupiter in this image was separately photographed at a different time by Hubble\u2019s Outer Planet Atmospheres Legacy (OPAL) program, a long-term Hubble project that annually captures global maps of the outer planets. Credit: NASA, ESA, and J. Nichols (University of Leicester)<\/figcaption><\/figure><\/div>\n\n\n\n


The study, published in the\u00a0Journal of Geophysical Research: Space Physics<\/em>, describes the delicate current cycle driven by Jupiter\u2019s rapid rotation and the release of sulphur and oxygen from volcanoes on its moon, Io.

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Researchers from the University of Leicester\u2019s School of Physics and Astronomy used data from Juno\u2019s Magnetic Field Investigation (MAG), which measures Jupiter\u2019s magnetic field from orbit around the gas giant, and observations from the Space Telescope Imaging Spectrograph carried by the Hubble Space Telescope.

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Their research provides the strongest evidence yet that Jupiter\u2019s powerful aurorae are associated with an electric current system that acts as part of a tug-of-war with material in the magnetosphere, the region dominated by the planet\u2019s enormous magnetic field.

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Illustration of the mechanism behind Jupiter\u2019s \u2018tug-of-war\u2019 \u2013 the delicate current cycle driven by Jupiter\u2019s rapid rotation and the release of sulphur and oxygen from volcanoes on its moon, Io. Credit: Emma Bunce\/Stanley Cowley\/Jonathan Nichols\/University of Leicester<\/figcaption><\/figure><\/div>\n\n\n\n

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Dr Jonathan Nichols is a Reader in Planetary Auroras at the University of Leicester and corresponding author for the study. He said: \u201cWe\u2019ve had theories linking these electric currents and Jupiter\u2019s powerful auroras for over two decades now, and it was so exciting to be able to finally test them by looking for this relationship in the data. And when we plotted one against the other I nearly fell off my chair when I saw just how clear the connection is.

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\u201cIt\u2019s thrilling to discover this relation because it not only helps us understand how Jupiter\u2019s magnetic field works, but also those of planets orbiting other stars, for which we have previously used the same theories, and now with renewed confidence.\u201d

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Despite its huge size \u2013 with a diameter more than 11 times that of Earth \u2013 Jupiter rotates once approximately every nine-and-a-half hours.

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Io is a similar size and mass to Earth\u2019s moon, but orbits Jupiter at an average distance of 422,000 km; roughly 10% further away. With over 400 active volcanoes, Io is the most geologically active object in the Solar System.

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Scientists had long suspected a relationship between Jupiter\u2019s aurorae and the material ejected from Io at a rate of many hundreds of kilograms per second, but the data captured by Juno proved ambiguous.

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Dr Scott Bolton, of the Southwest Research Institute, San Antonio, is Principal Investigator (PI) for the Juno mission. He said: \u201cThese exciting results on how Jupiter\u2019s aurorae work are a testament to the power of combining Earth-based observations from Hubble with Juno measurements. The HST images provide the broad overview, while Juno investigates close up.\u00a0 Together they make a great team!\u201d

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Much of the material released from Io is propelled away from Jupiter by the planet\u2019s rapidly rotating magnetic field, and as it moves outward its rotation rate tends to slow down.\u00a0 This results in an electromagnetic tug-of-war, in which Jupiter attempts to keep this material spinning at its rotation speed via a system of electric currents flowing through the planet\u2019s upper atmosphere and magnetosphere.

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The component of the electric current flowing out of the planet\u2019s atmosphere, carried by electrons fired downward along magnetic field lines into the upper atmosphere, was thought to drive Jupiter\u2019s main auroral emission.

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However, prior to Juno\u2019s arrival this idea had never been tested, as no spacecraft with relevant instruments had previously orbited close enough to Jupiter. And when Juno arrived in 2016, the expected signature of such an electric current system was not reported \u2013 and, while such signatures have since been found \u2013 one of the great surprises of Juno\u2019s mission has been to show that the nature of the electrons above Jupiter\u2019s polar regions is much more complex than was initially expected.

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The researchers compared the brightness of Jupiter\u2019s main auroral emission with simultaneous measurements of the electric current flowing away from the Solar System\u2019s largest planet in the magnetosphere over an early part of Juno\u2019s mission.

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These aurorae were observed with instruments on board the Hubble Space Telescope, in Earth orbit. By comparing the dawn-side measurements of current with the brightness of Jupiter\u2019s aurorae, the team demonstrated the relationship between the auroral intensity and magnetospheric current strength.

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Stan Cowley is Emeritus Professor of Solar-Planetary Physics at the University of Leicester and co-author for the study, and has studied Jupiter\u2019s powerful aurorae for 25 years. Professor Cowley added: \u201cHaving more than five years of in-orbit data from the Juno spacecraft, together with auroral imaging data from the HST, we now have the material to hand to look in detail at the overall physics of Jupiter\u2019s outer plasma environment, and more is to come from Juno\u2019s extended mission, now in progress. We hope our present paper will be followed by many more exploring this treasure trove for new scientific understanding.\u201d

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Leicester research published in October 2021 \u2013 also using data captured by NASA\u2019s Juno probe \u2013\u00a0revealed new insights into the processes deep beneath the gas giant\u2019s distinctive and colourful bands<\/a>.

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\u2018Relation of Jupiter\u2019s dawnside main emission intensity to magnetospheric currents during the Juno mission<\/a>\u2019 is published in the Journal of Geophysical Research: Space Physics<\/em>.<\/p>\n","protected":false},"excerpt":{"rendered":"

New Leicester space research has revealed, for the first time, a complex \u2018tug-of-war\u2019 lights up aurorae in Jupiter\u2019s upper atmosphere, using a combination of data from NASA\u2019s Juno probe and the Hubble Space Telescope. The study, published in the\u00a0Journal of Geophysical Research: Space Physics, describes the delicate current cycle driven by Jupiter\u2019s rapid rotation and […]<\/p>\n","protected":false},"author":256,"featured_media":1359,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[],"class_list":["post-1357","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-planetary"],"_links":{"self":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts\/1357","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/users\/256"}],"replies":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/comments?post=1357"}],"version-history":[{"count":1,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts\/1357\/revisions"}],"predecessor-version":[{"id":1360,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/posts\/1357\/revisions\/1360"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/media\/1359"}],"wp:attachment":[{"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/media?parent=1357"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/categories?post=1357"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/physicsastronomy\/wp-json\/wp\/v2\/tags?post=1357"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}