{"592944":{"#nid":"592944","#data":{"type":"news","title":"Topsy-Turvy Motion Creates Light Switch Effect at Uranus","body":[{"value":"\u003Cp\u003EMore than 30 years after Voyager 2 sped past Uranus, Georgia Institute of Technology researchers are using the spacecraft\u0026rsquo;s data to learn more about the icy planet. Their new study suggests that Uranus\u0026rsquo; magnetosphere, the region defined by the planet\u0026rsquo;s magnetic field and the material trapped inside it, gets flipped on and off like a light switch every day as it rotates along with the planet. It\u0026rsquo;s \u0026ldquo;open\u0026rdquo; in one orientation, allowing solar wind to flow into the magnetosphere; it later closes, forming a shield against the solar wind and deflecting it away from the planet.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThis is much different from Earth\u0026rsquo;s magnetosphere, which typically only switches between open and closed in response to changes in the solar wind. Earth\u0026rsquo;s magnetic field is nearly aligned with its spin axis, causing the entire magnetosphere to spin like a top along with the Earth\u0026rsquo;s rotation. Since the same alignment of Earth\u0026rsquo;s magnetosphere is always facing toward the sun, the magnetic field threaded in the ever-present solar wind must change direction in order to reconfigure Earth\u0026rsquo;s field from closed to open. This frequently occurs with strong solar storms.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EBut Uranus lies and rotates on its side, and its magnetic field is lopsided \u0026mdash; it\u0026rsquo;s off-centered and tilted 60 degrees from its axis. Those features cause the magnetic field to tumble asymmetrically\u0026nbsp;relative to the solar wind direction as the icy giant completes its 17.24-hour full rotation.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ERather than the solar wind dictating a switch like here on Earth, the researchers say Uranus\u0026rsquo; rapid rotational change in field strength and orientation lead to a periodic open-close-open-close scenario as it tumbles through the solar wind.\u003Cbr \/\u003E\r\n\u003Cbr \/\u003E\r\n\u0026ldquo;Uranus is a geometric nightmare,\u0026rdquo; said \u003Ca href=\u0022http:\/\/www.eas.gatech.edu\/people\/Carol_Paty\u0022\u003ECarol Paty\u003C\/a\u003E, the Georgia Tech associate professor who co-authored the study. \u0026ldquo;The magnetic field tumbles very fast, like a child cartwheeling down a hill head over heels. When the magnetized solar wind meets this tumbling field in the right way, it can reconnect and Uranus\u0026rsquo; magnetosphere goes from open to closed to open on a daily basis.\u0026rdquo;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EPaty says this solar wind reconnection is predicted to occur upstream of Uranus\u0026rsquo; magnetosphere over a range of latitudes, with magnetic flux closing in various parts of the planet\u0026rsquo;s twisted magnetotail.\u003Cs\u003E \u0026nbsp;\u003C\/s\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EReconnection of magnetic fields is a phenomenon throughout the solar system. It occurs when the direction of the interplanetary magnetic field \u0026ndash; which comes from the sun and is also known as the heliospheric magnetic field \u0026ndash; is opposite a planet\u0026rsquo;s magnetospheric alignment. Magnetic field lines are then spliced together and rearrange the local magnetic topology, allowing a surge of solar energy to enter the system.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EMagnetic reconnection is one reason for Earth\u0026rsquo;s auroras. Auroras could be possible at a range of latitudes on Uranus due to its off-kilter magnetic field, but the aurora is difficult to observe because the planet is nearly 2 billion miles from Earth. The Hubble Space Telescope occasionally gets a faint view, but it can\u0026rsquo;t directly measure Uranus\u0026rsquo; magnetosphere.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe Georgia Tech researchers used numerical models to simulate the planet\u0026rsquo;s global magnetosphere and to predict favorable reconnection locations. They plugged in data collected by Voyager 2 during its five-day flyby in 1986. It\u0026rsquo;s the only time a spacecraft has visited.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe researchers say learning more about Uranus is one key to discovering more about planets beyond our solar system.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;The majority of exoplanets that have been discovered appear to also be ice giants in size,\u0026rdquo; said Xin Cao, the Georgia Tech Ph.D. candidate in earth and atmospheric sciences who led the study. \u0026ldquo;Perhaps what we see on Uranus and Neptune is the norm for planets: very unique magnetospheres and less-aligned magnetic fields. Understanding how these complex magnetospheres shield exoplanets from stellar radiation is of key importance for studying the habitability of these newly discovered worlds.\u0026rdquo;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe paper, \u0026ldquo;\u003Ca href=\u0022http:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/2017JA024063\/full\u0022\u003EDiurnal and Seasonal Variability of Uranus\u0026rsquo; Magnetosphere\u003C\/a\u003E,\u0026rdquo; is currently published in the Journal of Geophysical Research: Space Physics.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Unlike Earth, this icy planet\u2019s magnetosphere opens and closes every day"}],"field_summary":[{"value":"\u003Cp\u003EUranus\u0026rsquo; magnetosphere, the region defined by the planet\u0026rsquo;s magnetic field and the material trapped inside it, gets flipped on and off like a light switch every day as it rotates along with the planet. It\u0026rsquo;s \u0026ldquo;open\u0026rdquo; in one orientation, allowing solar wind to flow into the magnetosphere; it later closes, forming a shield against the solar wind and deflecting it away from the planet.\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"Uranus\u2019 magnetosphere gets flipped on and off like a light switch every day as it rotates along with the planet."}],"uid":"27560","created_gmt":"2017-06-26 12:03:36","changed_gmt":"2017-06-26 12:25:27","author":"Jason Maderer","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2017-06-26T00:00:00-04:00","iso_date":"2017-06-26T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"592942":{"id":"592942","type":"image","title":"Uranus Aurora","body":null,"created":"1498478256","gmt_created":"2017-06-26 11:57:36","changed":"1498478256","gmt_changed":"2017-06-26 11:57:36","alt":"Uranus Auroras","file":{"fid":"226008","name":"Uranus 2.jpg","image_path":"\/sites\/default\/files\/images\/Uranus%202.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/Uranus%202.jpg","mime":"image\/jpeg","size":70612,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/Uranus%202.jpg?itok=QhIUkct6"}},"592943":{"id":"592943","type":"image","title":"Uranus","body":null,"created":"1498478333","gmt_created":"2017-06-26 11:58:53","changed":"1498478333","gmt_changed":"2017-06-26 11:58:53","alt":"Uranus","file":{"fid":"226010","name":"Uranus.png","image_path":"\/sites\/default\/files\/images\/Uranus.png","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/Uranus.png","mime":"image\/png","size":462411,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/Uranus.png?itok=LotvpQo_"}}},"media_ids":["592942","592943"],"related_links":[{"url":"http:\/\/www.news.gatech.edu\/2017\/03\/27\/electric-sands-titan","title":"The Sands of Titan Would Create Great Sand Castles"},{"url":"http:\/\/www.news.gatech.edu\/2015\/06\/01\/faculty-selected-co-investigators-nasa-mission-europa","title":"Paty, Schmidt Involved in Future Europa Mission"},{"url":"http:\/\/www.news.gatech.edu\/2017\/02\/22\/search-life-solar-system","title":"The Search for Life in the Solar System"}],"groups":[{"id":"1214","name":"News Room"},{"id":"1278","name":"College of Sciences"},{"id":"364801","name":"EAS"}],"categories":[{"id":"135","name":"Research"}],"keywords":[{"id":"174765","name":"Uranus"},{"id":"174766","name":"Magnetosphere"},{"id":"127551","name":"Carol Paty"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"}],"news_room_topics":[{"id":"71881","name":"Science and Technology"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJason Maderer\u003Cbr \/\u003E\r\nNational Media Relations\u003Cbr \/\u003E\r\nmaderer@gatech.edu\u003Cbr \/\u003E\r\n404-660-2926\u003C\/p\u003E\r\n","format":"limited_html"}],"email":["maderer@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}