Juno&#8217;s Exploration of Jupiter&#8217;s Magnetic Field and Magnetosphere
Authors: Connerney Jack , Oliverson Ron , Kotsiaros Stavros , Gershman Dan , Martos Yasmina , Joergensen John , Joergensen Peter , Merayo Jose , Herceg Matija , Benn Mathias , Denver Troelz , Bloxham Jeremy , Moore Kimberly , Bolton Scott , Levin Steven 
Published: March 2020

&lt;p&gt;The Juno spacecraft was inserted into polar orbit about Jupiter on July 4&lt;sup&gt;th&lt;/sup&gt;, 2016, performing close passes (to ~1.05 Rj radial distance at periJove) every 53 days. By the end of its prime mission, Juno will have circled the planet 34 times, uniformly sampling longitudes separated by less than 11&lt;img src=&quot;data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAASABIAAD/4QB0RXhpZgAATU0AKgAAAAgABAEaAAUAAAABAAAAPgEbAAUAAAABAAAARgEoAAMAAAABAAIAAIdpAAQAAAABAAAATgAAAAAAAABIAAAAAQAAAEgAAAABAAKgAgAEAAAAAQAAAASgAwAEAAAAAQAAABkAAAAA/+0AOFBob3Rvc2hvcCAzLjAAOEJJTQQEAAAAAAAAOEJJTQQlAAAAAAAQ1B2M2Y8AsgTpgAmY7PhCfv/AABEIABkABAMBIgACEQEDEQH/xAAfAAABBQEBAQEBAQAAAAAAAAAAAQIDBAUGBwgJCgv/xAC1EAACAQMDAgQDBQUEBAAAAX0BAgMABBEFEiExQQYTUWEHInEUMoGRoQgjQrHBFVLR8CQzYnKCCQoWFxgZGiUmJygpKjQ1Njc4OTpDREVGR0hJSlNUVVZXWFlaY2RlZmdoaWpzdHV2d3h5eoOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3uLm6wsPExcbHyMnK0tPU1dbX2Nna4eLj5OXm5+jp6vHy8/T19vf4+fr/xAAfAQADAQEBAQEBAQEBAAAAAAAAAQIDBAUGBwgJCgv/xAC1EQACAQIEBAMEBwUEBAABAncAAQIDEQQFITEGEkFRB2FxEyIygQgUQpGhscEJIzNS8BVictEKFiQ04SXxFxgZGiYnKCkqNTY3ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqCg4SFhoeIiYqSk5SVlpeYmZqio6Slpqeoqaqys7S1tre4ubrCw8TFxsfIycrS09TV1tfY2dri4+Tl5ufo6ery8/T19vf4+fr/2wBDAAICAgICAgMCAgMFAwMDBQYFBQUFBggGBgYGBggKCAgICAgICgoKCgoKCgoMDAwMDAwODg4ODg8PDw8PDw8PDw//2wBDAQICAgQEBAcEBAcQCwkLEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBD/3QAEAAH/2gAMAwEAAhEDEQA/AN/x7438bX8XhaSG68b6GU0GwVxD4p8QRfan2szXL+dPbbpHJ2uyCVCVO2aQDI8//wCEp8ef9DP49/8ACt1r/wCWFfX/AMXPhv8AHvxOPBQ0P4T61c/2R4Z03T7r/T9BTy7q38zzI/n1Rd23cPmXKnsTXkH/AAo/9pj/AKI9rX/gy8Pf/LagD//Q/fyiiigD/9k=&quot; width=&quot;4&quot; height=&quot;13&quot;&gt;&amp;#160;at the equator. The Juno magnetic field investigation is equipped with two magnetometer sensor suites, located at 10 and 12 m from the spacecraft body at the end of one of Juno&amp;#8217;s three solar arrays. Each contains a vector fluxgate magnetometer (FGM) sensor and a pair of co-located non-magnetic star tracker camera heads that provide accurate attitude determination for the FGM sensors. A moredetailed view of Jupiter&amp;#8217;s planetary dynamo is emerging as Juno acquires more periJove passes, providing spatial resolution beyond that already evident in the preliminary model (JRM09, a degree 10 spherical harmonic) derived from Juno&amp;#8217;s first 9 periJoves. A complex and very non-dipolar magnetic field dominates the northern hemisphere, while a mostly dipolar magnetic field is observed south of the equator, where the enigmatic &amp;#8220;Great Blue Spot&amp;#8221; resides within an equatorial band of opposite polarity. The Jovian magnetodisc, formed by a washer-shaped disc of azimuthal (&amp;#8220;ring&amp;#8221;) currents, stretches magnetic field lines outward along the magnetic equator. With 26 equally spaced longitudes now available we can begin to address magnetodisc variability, finding a more or less stable system of azimuthal ring currents (few % variability) and a more variable (~50%) system of radial currents that supply torque to outflowing plasma. A new magnetodisc model greatly improves knowledge of the field geometry, independently verified via observations of the particle absorption signatures of Galilean satellites. A more systematic mapping of Birkeland currents above the polar aurorae also emerges from multiple passes. These and other developments will be presented with Juno now about &amp;#190; of the way towards completion of its primary mission.&lt;/p&gt;