{"id":6446,"date":"2013-09-27T14:40:41","date_gmt":"2013-09-27T21:40:41","guid":{"rendered":"http:\/\/planets.ucla.edu\/?p=6446"},"modified":"2021-01-18T01:35:55","modified_gmt":"2021-01-18T09:35:55","slug":"graduate-student-hao-cao-decodes-planetary-magnetic-fields","status":"publish","type":"post","link":"http:\/\/planets.ucla.edu\/?p=6446","title":{"rendered":"Graduate student Hao Cao decodes planetary magnetic fields"},"content":{"rendered":"

\"HaoCao\"<\/a>Long ago, scientists discovered that when a compass points north on Earth, it is not actually pointing to the North Pole.\u00a0 The axis of Earth\u2019s magnetic field is tilted away from the axis that the planet spins about. Every planet in our solar system with a magnetic field follows this rule, except one: Saturn.<\/p>\n

When fourth-year graduate student Hao Cao came to UCLA, his advisor, Professor Chris Russell, presented him the opportunity to study data from NASA\u2019s Cassini mission.\u00a0 Arriving at Saturn in 2004, Cassini has been orbiting the planet ever since, measuring Saturn\u2019s magnetic field, among many other things.\u00a0 Cao wondered, \u201cWhat does the magnetic field tell us about Saturn?\u201d<\/p>\n

To answer that question, Cao needed to determine how Saturn\u2019s magnetic field is generated.\u00a0 The sixth planet from the Sun, Saturn is a gas giant composed primarily of hydrogen, the simplest and most abundant of elements in the universe.\u00a0 Inside Saturn, where pressure is a million times greater than at Earth\u2019s surface, hydrogen is thought to exist as liquid metal. The turbulent motions of this electrically conductive hydrogen are what give rise to the magnetic field of Saturn.\u00a0 But metallic hydrogen is also responsible for producing the tilted magnetic field on Jupiter.\u00a0 Cao knew he had to look deeper.<\/p>\n

He began contemplating the rocky core that may exist deep in the heart of Saturn, which could shape the metallic hydrogen layer that lies above it. \u201cZonal winds that move across the planet could reach deep inside the planet and influence the shape of the magnetic field being generated by the metallic hydrogen layer,\u201d said Cao.\u00a0 As a result of these interactions, Cao has produced the best size estimate of Saturn\u2019s core to date.\u00a0 Twice the size and ten times the mass of Earth, but only 1\/5th the size of Saturn, this core is the first to be assessed using magnetic field data.<\/p>\n

Recently, Cao has begun trying to explain Mercury\u2019s puzzling asymmetric magnetic field using information from NASA\u2019s MESSENGER spacecraft.\u00a0 \u201cWhen you study a place like Saturn or Mercury, there are many things you learn for the first time,\u201d said Cao.\u00a0 Beyond magnetic field research, Cao is interested in many aspects of planetary science.\u00a0 \u201cDynamo studies are only part of understanding planets. Formation, internal structure, and dynamics are all related \u2013 it\u2019s not an isolated problem,\u201d he said.<\/p>\n

Watch a video profile of Hao Cao here<\/a>.\u00a0 Learn more about his research here<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Long ago, scientists discovered that when a compass points north on Earth, it is not actually pointing to the North Pole.\u00a0 The axis of Earth\u2019s magnetic field is tilted away from the axis that the planet spins about. Every planet in our solar system with a magnetic field follows this rule, except one: Saturn. When … <\/p>\n

Continue reading “Graduate student Hao Cao decodes planetary magnetic fields”<\/span><\/a><\/p>\n","protected":false},"author":9,"featured_media":8633,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[325,326,317],"class_list":["post-6446","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-hao-cao","tag-magnetic-field","tag-planets"],"_links":{"self":[{"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/posts\/6446","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6446"}],"version-history":[{"count":9,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/posts\/6446\/revisions"}],"predecessor-version":[{"id":8634,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/posts\/6446\/revisions\/8634"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=\/wp\/v2\/media\/8633"}],"wp:attachment":[{"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6446"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6446"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/planets.ucla.edu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6446"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}