{"id":15243832,"date":"2026-08-06T13:26:40","date_gmt":"2026-08-06T17:26:40","guid":{"rendered":"https:\/\/www.inthacity.com\/news\/super-earths-may-be-solid-deep-inside-their-mantles\/"},"modified":"2026-08-06T13:33:23","modified_gmt":"2026-08-06T17:33:23","slug":"super-earths-may-be-solid-deep-inside-their-mantles","status":"publish","type":"post","link":"https:\/\/www.inthacity.com\/news\/super-earths-may-be-solid-deep-inside-their-mantles\/","title":{"rendered":"Super-Earths May Be Solid Deep Inside Their Mantles"},"content":{"rendered":"<figure><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/eos.org\/wp-content\/uploads\/2026\/08\/super-earth-lp8909c5-1024x576.jpg\" class=\"attachment-rss-image-size size-rss-image-size wp-post-image\" alt=\"Super-Earth LP 890-9 c is seen in an artist\u2019s concept.\" \/><\/figure>\n<h5 class=\"wp-block-heading\">Source:<em> <a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/journal\/2576604x\" target=\"_blank\" rel=\"noreferrer noopener\"><em>AGU Advances<\/em><\/a><\/em><\/h5>\n<p>Deep inside super-Earths\u2014rocky planets with a mass anywhere between 1 and 10 times that of Earth\u2014high pressure can cause familiar minerals to take forms that are rarely seen on Earth. Understanding more about the temperature and pressure conditions under which these phases are reached could help researchers learn more about how planets evolve.<\/p>\n<p>One such mineral is magnesium orthosilicate, or Mg<sub>2<\/sub>SiO<sub>4<\/sub>, one of the major building blocks of rocky planets. As pressure increases deep inside a planet, the atoms in this mineral rearrange into different crystal structures. One of these high-pressure forms is called the spinel phase, which is found in Earth\u2019s mantle. At even higher pressures, this phase breaks down into two different minerals: bridgmanite, the most abundant mineral phase in Earth, and ferropericlase, a magnesium-rich oxide. However, under the far more extreme pressures expected inside massive rocky planets known as super-Earths, Mg<sub>2<\/sub>SiO<sub>4<\/sub> becomes stable again in an entirely new crystal structure called post-post-spinel. Scientists predict that this ultrahigh-pressure phase of Mg<sub>2<\/sub>SiO<sub>4<\/sub> is one of the dominant minerals in the deep mantles of super-Earths, making its melting behavior important for understanding how these planets form and evolve.<\/p>\n<p>Re-creating the high temperatures and extraordinary pressures inside massive rocky planets is challenging in the lab, so <a href=\"https:\/\/doi.org\/10.1029\/2026AV002326\" target=\"_blank\" rel=\"noreferrer noopener\"><em>Zheng et al.<\/em><\/a> took a computational approach. The team used a technique called thermodynamic integration to study the melting curve of post-post-spinel Mg<sub>2<\/sub>SiO<sub>4<\/sub> at up to 1,300 gigapascals of pressure.<\/p>\n<p>They found that post-post-spinel Mg<sub>2<\/sub>SiO<sub>4<\/sub> is an exceptionally refractory mineral, meaning it can withstand extremely high temperatures before melting. Depending on the pressure, it melts at between 9,780 K and 14,897 K, significantly hotter than temperatures at which related minerals melt, including bridgmanite and MgSiO<sub>3<\/sub> postperovskite, the high-pressure form of bridgmanite stable near Earth\u2019s core-mantle boundary. Even after moderate amounts of iron were added, something that likely happens to some degree in most exoplanets, the melting point for post-post-spinel Mg<sub>2<\/sub>SiO<sub>4<\/sub> remained above the temperatures estimated for the deep mantles of most rocky planets, the authors say.<\/p>\n<p>Their results indicate that many super-Earths likely have solid deep mantles, which has implications for convection deep inside rocky exoplanets, as well as for their magnetic fields, which are created by swirling molten metals in their interiors. (<em>AGU Advances<\/em>, <a href=\"https:\/\/doi.org\/10.1029\/2026AV002326\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/doi.org\/10.1029\/2026AV002326<\/a>, 2026)<\/p>\n<p>\u2014Nathaniel Scharping (<a href=\"https:\/\/x.com\/NathanielScharp\" target=\"_blank\" rel=\"noreferrer noopener\">@nathanielscharp<\/a>), Science Writer<\/p>\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.agu.org\/give-to-agu\/giving?utm_source=Donate_Button_Eos&amp;utm_medium=referral&amp;utm_campaign=eos_bottom_research_spotlights\" target=\"_blank\" rel=\" noreferrer noopener\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"213\" src=\"https:\/\/eos.org\/wp-content\/uploads\/2025\/04\/donate-today-1024x213.png\" alt=\"A photo of a telescope array appears in a circle over a field of blue along with the Eos logo and the following text: Support Eos\u2019s mission to broadly share science news and research. Below the text is a darker blue button that reads \u201cdonate today.\u201d\" class=\"wp-image-235350\" \/><\/a><\/figure>\n<h5 class=\"wp-block-heading\"><strong>Citation:<\/strong>\u00a0Scharping, N. (2026), Super-Earths may be solid deep inside their mantles,\u00a0<em>Eos, 107, <\/em><a href=\"https:\/\/doi.org\/10.1029\/2026EO260256\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/doi.org\/10.1029\/2026EO260256<\/a>. Published on 7 August 2026.<\/h5>\n<h6 class=\"wp-block-heading\">Text \u00a9 2026. AGU.\u00a0<a href=\"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0\/us\/\" target=\"_blank\" rel=\"noreferrer noopener\">CC BY-NC-ND 3.0<\/a><br \/>Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.<\/h6>\n<p class=\"inmi-source\">Source: <a href=\"https:\/\/eos.org\/research-spotlights\/super-earths-may-be-solid-deep-inside-their-mantles\" target=\"_blank\" rel=\"noopener nofollow\">Science \u2013 eos<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>New estimates show that a mineral likely common in these rocky planets\u2019 interiors is resistant to melting, even at high temperatures.<\/p>\n","protected":false},"author":1,"featured_media":15243834,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[218],"tags":[],"class_list":["post-15243832","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science"],"featured_image_urls":{"full":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1.jpg",1024,576,false],"thumbnail":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-300x169.jpg",300,169,true],"medium":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-620x349.jpg",620,349,true],"medium_large":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-768x432.jpg",768,432,true],"large":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-940x529.jpg",940,529,true],"1536x1536":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1.jpg",1024,576,false],"2048x2048":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1.jpg",1024,576,false],"post-thumbnail":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-998x576.jpg",998,576,true],"ignition_item":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-670x446.jpg",670,446,true],"ignition_item_lg":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1.jpg",1024,576,false],"ignition_article_media":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-510x510.jpg",510,510,true],"ignition_minicart_item":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-160x160.jpg",160,160,true],"profile_24":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-24x24.jpg",24,24,true],"profile_48":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-48x48.jpg",48,48,true],"profile_96":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-96x96.jpg",96,96,true],"profile_150":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-150x150.jpg",150,150,true],"profile_300":["https:\/\/www.inthacity.com\/news\/wp-content\/uploads\/2026\/08\/15243832-super-earth-lp8909c5-1024x576-1-300x300.jpg",300,300,true]},"author_info":{"display_name":"news.iNthacity","author_link":"https:\/\/www.inthacity.com\/news\/author\/atombo\/"},"category_info":"<a href=\"https:\/\/www.inthacity.com\/news\/articles\/science\/\" rel=\"category tag\">Science<\/a>","tag_info":"Science","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts\/15243832","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/comments?post=15243832"}],"version-history":[{"count":1,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts\/15243832\/revisions"}],"predecessor-version":[{"id":15243833,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/posts\/15243832\/revisions\/15243833"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/media\/15243834"}],"wp:attachment":[{"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/media?parent=15243832"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/categories?post=15243832"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.inthacity.com\/news\/wp-json\/wp\/v2\/tags?post=15243832"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}