KINGSTON, R.I. \u2013 April 1, 2019 \u2013 Little is known about the inner structure of the moon, but a major step forward was made by a 溏心vlog免费B站 scientist who conducted experiments that enabled her to determine the temperature at the boundary of the moon\u2019s core and mantle.<\/p>\n
She found the temperature to be between 1,130 and 1,470 degrees Celsius, which is at the high end of an 800 degree range that previous scientists had determined.<\/p>\n
\u201cIn order to understand the interior structure of the moon today, we needed to nail down the thermal state better,\u201d said Ananya Mallik, a 溏心vlog免费B站 assistant professor of geosciences who joined the University faculty in December 2018. \u201cNow we have the two anchor points \u2013 the core-mantle boundary and the surface temperature measured by Apollo \u2013 and that will help us create a temperature profile through the moon. We need that temperature profile to determine the internal state, structure and composition of the moon.\u201d<\/p>\n
The surface temperature of the moon is approximately -20 C.<\/p>\n
According to Mallik, the moon has an iron core, like that of Earth, and previous research using seismic data had found that between 5 and 30 percent of the material at the boundary of the core and mantle was in a liquid or molten state.<\/p>\n
\u201cThe big question is, why would we have some melt present in the moon at that depth,\u201d Mallik said.<\/p>\n
To begin to answer this question, Mallik conducted a series of experiments in 2016 at the Bavarian Research Institute of Experimental Geochemistry and Geophysics in Germany using a multi-anvil device that can exert the high pressures found deep inside the moon. She prepared a tiny sample of material similar to that found on the moon, squeezed it in the device at 45,000 times the Earth\u2019s atmospheric pressure, which is the pressure believed to exist at the moon\u2019s core-mantle boundary, and used a graphite heater to raise the temperature of the sample until it partially melted.<\/p>\n
\u201cThe goal was to determine what temperature range would produce a 5 to 30 percent melt, which would tell us the temperature range of the core-mantle boundary,\u201d she said.<\/p>\n
Now that the temperature range at the boundary has been narrowed, scientists can begin to develop a more precise temperature profile of the moon and proceed to determine a profile of the minerals that make up the mantle from its crust to its core.<\/p>\n
\u201cIt\u2019s important that we know the composition of the moon to better understand why it has evolved as it has,\u201d Mallik said. \u201cThe histories of the Earth and moon have been intertwined since the beginning. In fact, both are the product of a great collision between proto-Earth and an approximately Mars-sized body that occurred over 4.5 billion years ago. So to understand our Earth better, we have to know our nearest neighbor because we all had a common start.<\/p>\n
\u201cEarth is complicated,\u201d she continued. \u201cAny similarity in the composition between Earth and the moon can give us insight into how these two planetary bodies were formed, what were the energetics of the collision, and how elements were partitioned between them.\u201d<\/p>\n
The 溏心vlog免费B站 geoscientist noted that Earth has evolved through the process of plate tectonics, which is responsible for the distribution of the continents, the topography of Earth\u2019s surface, the regulation of long-term climate, and perhaps even the origin of life. But there is no evidence of plate tectonics on the moon.<\/p>\n
\u201cEverything on Earth happens because of plate tectonics,\u201d she said. \u201cWhat does this tell us about our own planet when the moon doesn\u2019t experience this process? It\u2019s the same argument for why we study Mars and Venus. They are our next closest neighbors, and we all had a common start, but why are they so different from our planet?\u201d<\/p>\n
The next steps in Mallik\u2019s research will involve experimentally determining the density of the molten material at the core-mantle boundary, which will further refine the temperature range. In collaboration with Heidi Fuqua Haviland at NASA\u2019s Marshall Space Flight Center and Paul Bremner at the University of Florida, she will then combine these results with computational methods to derive the temperature profile and composition of the interior of the moon.<\/p>\n
Mallik\u2019s research was published April 1 in the journal Geochimica et Cosmochimica<\/em><\/p>\n Acta<\/em>. Co-authors are Tariq Ejaz, a graduate student at the National Center for Antarctic and Ocean Research in India; Svyatoslav Shcheka, a postdoctoral researcher at the Bavarian Research Institute of Experimental Geochemistry and Geophysics in Germany; and Gordana Garapic, assistant professor at the State University of New York at New Paltz.<\/p>\n","protected":false},"excerpt":{"rendered":" KINGSTON, R.I. \u2013 April 1, 2019 \u2013 Little is known about the inner structure of the moon, but a major step forward was made by a 溏心vlog免费B站 scientist who conducted experiments that enabled her to determine the temperature at the boundary of the moon\u2019s core and mantle. She found the temperature to […]<\/p>\n","protected":false},"author":2,"featured_media":74658,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[],"class_list":["post-74657","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-archives"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/74657","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/comments?post=74657"}],"version-history":[{"count":0,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/posts\/74657\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/media\/74658"}],"wp:attachment":[{"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/media?parent=74657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/categories?post=74657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.uri.edu\/news\/wp-json\/wp\/v2\/tags?post=74657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}