{"id":32,"date":"2016-06-27T16:44:13","date_gmt":"2016-06-27T16:44:13","guid":{"rendered":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/?p=32"},"modified":"2025-02-26T13:28:20","modified_gmt":"2025-02-26T13:28:20","slug":"jupiters-aurora-the-most-powerful-northern-lights-display-in-the-solar-system","status":"publish","type":"post","link":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/2016\/06\/27\/jupiters-aurora-the-most-powerful-northern-lights-display-in-the-solar-system\/","title":{"rendered":"Jupiter’s aurora: the most powerful Northern lights display in the solar system!"},"content":{"rendered":"

During Juno\u2019s time at Jupiter, we will have the fantastic opportunity to study the most powerful aurora in the solar system. An aurora is light emitted by atoms and molecules that have been excited through collisions with very energetic particles that enter a planet\u2019s atmosphere along the planet\u2019s magnetic field lines. The generation of Jupiter\u2019s aurora is vastly different to the processes that create the Earth\u2019s aurora and by studying this, we can gain a better understanding of space weather and how the planets interact with it.<\/p>\n

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In the case of the Earth\u2019s aurora, the process starts off at the sun, where particles are constantly flowing out into space and dragging the Sun\u2019s magnetic field with them. The particles and magnetic field together are known as the solar wind. The Earth\u2019s aurora is generated through the connection between the solar wind and the Earth\u2019s magnetic field; however the situation is very different at Jupiter.<\/p>\n

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\"Jupiter\u2019s

Jupiter\u2019s magnetosphere \u2013 the magnetic bubble which surrounds Jupiter. Credit: NASA.<\/p><\/div>\n

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\"The

The volcanic moon: Io. Credit: NASA.<\/p><\/div>\n

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The generation of the aurora is different at Jupiter for two main reasons. Jupiter\u2019s magnetic field is incredibly strong, about ten times the strength of the Earth\u2019s magnetic field. If it were possible to view the invisible magnetic field lines that surround Jupiter, known collectively as the magnetosphere, they would fill an area in the night sky which was larger than the moon! The first reason is that Jupiter\u2019s magnetosphere is full of charged particles, known as plasma. Unlike the Earth\u2019s quiet moon, the Galilean moon Io has sulphurous volcanoes which eject one tonne of material per second that is quickly turned into charged particles. The second reason is that Jupiter\u2019s magnetosphere is rotating very quickly. It spins with the planet, completing one revolution taking about 10 hours. Being fast and full of plasma makes Jupiter\u2019s magnetosphere a very different environment to the Earth\u2019s magnetosphere.<\/p>\n

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Imagine you\u2019ve made a line of people and asked them all to hold hands and you stand on the spot and spin them around you. Maybe you\u2019re mean and try to spin them really fast and you\u2019ll notice that the person on the end of the chain has to run the fastest to keep up. At some point they can\u2019t run fast enough and eventually they break the chain. This is essentially what happens at Jupiter to create the aurora, but instead of people there is plasma, and instead of arms there are magnetic fields.<\/p>\n

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In space plasma physics charged particles and magnetic field lines are intertwined. So as the plasma spins around Jupiter (just like you were spinning those people around), the magnetic field lines (everyone\u2019s arms) get dragged with it all. All this stuff is spinning around Jupiter, moving faster and faster as we move away from Jupiter until it cannot go any faster, causing the plasma and the magnetic field lines to slow down (just like that person who was stuck on the end that couldn\u2019t keep up). The consequence of having charged particles moving at different speeds relative to each other is that they make electrical currents. The electrical currents send electrons down the magnetic field lines and they accelerate into the Polar Regions, smashing into Jupiter\u2019s atmosphere and creating the main auroral emission.<\/p>\n

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\"Jupiter's<\/p>\n

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The generation of the main auroral emission is thought to be very well understood, but it behaves strangely when the pressure of the solar wind increases. When the solar wind pressure ramps up, Jupiter\u2019s main auroral emission has been observed to brighten, which is opposite to the expected behaviour calculated in models. If Juno is lucky enough to be at Jupiter during increased solar wind pressure, we will be able to collect measurements from inside the magnetosphere and pin-point the processes behind this strange behaviour.<\/p>\n

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Not only does Jupiter have main auroral emission, there are also the footprint auroras from the Galilean moons. Through the direct connection of magnetic field lines to the moons, Io, Europa, Ganymede and Castillo, spots and arcs are created in Jupiter\u2019s aurora. The footprint aurora are crucial in creating models of Jupiter\u2019s magnetic field and alongside the measurements taken with Juno, we will be able to create amazingly accurate models of the magnetic field to understand the whole system more completely.<\/p>\n

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The final component of Jupiter\u2019s magnetic field is the most controversial. Poleward of the main auroral emission is the polar aurora which is highly variable \u2013 scientists observe arcs, spots and patches. Exactly how this aurora is generated is not fully understood. Some researchers believe that the processes that occur here may be similar to the interaction between the Earth\u2019s magnetosphere and the solar wind. Others believe that the magnetosphere of Jupiter is completely closed to the solar wind. Already we have tantalising evidence that Jupiter is connected to the solar wind but exactly how, we do not know. And again this is where Juno\u2019s data will be the key in discovering the answers to one of the most pressing questions in space physics.<\/p>\n

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We can apply what we learn about Jupiter\u2019s magnetosphere to the Earth\u2019s magnetosphere. Although the magnetosphere\u2019s of Jupiter and Earth are different, studying other planets provides a natural laboratory in which the conditions of the experiment change at each planet. Understanding magnetosphere\u2019s is not only important for the satellites and astronauts that orbit the Earth, but will be crucial for future space exploration and the potential industrialisation or colonisation of Jupiter’s moons.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

During Juno\u2019s time at Jupiter, we will have the fantastic opportunity to study the most powerful aurora in the solar system. An aurora is light emitted by atoms and molecules that have been excited through collisions with very energetic particles that enter a planet\u2019s atmosphere along the planet\u2019s magnetic field lines. The generation of Jupiter\u2019s […]<\/p>\n","protected":false},"author":257,"featured_media":90,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[12,7,11,13],"class_list":["post-32","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science","tag-aurora","tag-juno","tag-jupiter","tag-space-weather"],"_links":{"self":[{"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/posts\/32","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/users\/257"}],"replies":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/comments?post=32"}],"version-history":[{"count":5,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/posts\/32\/revisions"}],"predecessor-version":[{"id":40,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/posts\/32\/revisions\/40"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/media\/90"}],"wp:attachment":[{"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/media?parent=32"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/categories?post=32"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/staffblogs.le.ac.uk\/leicester-to-jupiter\/wp-json\/wp\/v2\/tags?post=32"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}