WASHINGTON, May 16 \u2014 An exhaustive examination of lunar gravity using data obtained by two Nasa robotic spacecraft is offering new clues about why the two sides of the moon \u2014 the one perpetually facing Earth and the other always facing away \u2014 look so different.<\/p>\n
The data from the US space agency\u2019s Grail, or Gravity Recovery and Interior Laboratory, mission indicates that the moon\u2019s deep interior has an asymmetrical structure, apparently caused by intense volcanism on its nearside billions of years ago that helped shape its surface features.<\/p>\n
The researchers discovered that the lunar nearside flexes slightly more than the farside during its elliptical orbit around Earth thanks to our planet\u2019s gravitational influence \u2014 a process called tidal deformation. This indicates differences in the two sides of the lunar interior, they said, specifically in the geological layer called the mantle.<\/p>\n
\u201cOur study shows that the moon\u2019s interior is not uniform: the side facing Earth \u2014 the nearside \u2014 is warmer and more geologically active deep down than the farside,\u201d said Ryan Park, supervisor of the Solar System Dynamics Group at Nasa\u2019s Jet Propulsion Laboratory in California and lead author of the study published on Wednesday in the journal Nature.<\/p>\n
The moon\u2019s nearside is covered by vast plains, called mare, formed from molten rock that cooled and solidified billions of years ago. Its farside has much more rugged terrain, with few plains.<\/p>\n
Some scientists have hypothesized that intense volcanism within the nearside that caused radioactive, heat-generating elements to accumulate on that side of the mantle drove the surface differences observed today. The new findings offer the strongest evidence yet to support this notion.<\/p>\n
The researchers estimated that the nearside mantle on average is about 100\u00b0-200\u00b0Celsius hotter than the farside, with the thermal difference perhaps sustained by radioactive decay of the elements thorium and titanium on the nearside.<\/p>\n
\u201cThe moon\u2019s nearside and farside look very different, as shown by differences in topography, crustal thickness and the amount of heat-producing elements inside,\u201d Park said.<\/p>\n
The moon\u2019s diameter of about 3,475 km is a bit more than a quarter of Earth\u2019s diameter. The lunar mantle is the layer located beneath the crust and above the core, spanning a depth about 35-1,400 km under the surface. The mantle makes up roughly 80 per cent of the moon\u2019s mass and volume and is composed mostly of the minerals olivine and pyroxene, similar to Earth\u2019s mantle.<\/p>\n
\u201cThe fact that the detected asymmetry in the mantle matches the pattern of the surface geology \u2014 for instance, differences in the abundance of the approximately 3-4 billion-year-old mare basalts (volcanic rock) between the nearside and the farside \u2014 suggests that processes which drove ancient lunar volcanism are active today,\u201d said Caltech computational planetary scientist and study co-author Alex Berne, affiliated with the Jet Propulsion Laboratory working on the design of gravity sensors for missions to the outer solar system.<\/p>\n
The researchers spent years analyzing data from Grail\u2019s Ebb and Flow spacecraft, which orbited the moon from December 2011 to December 2012.<\/p>\n
\u201cOur study delivers the most detailed and accurate gravitational map of the moon to date,\u201d Park said.<\/p>\n
\u201cThis enhanced gravity map is a critical foundation for developing lunar Positioning, Navigation and Timing (PNT) systems, which are essential for the success of future lunar exploration missions. By improving our understanding of the moon\u2019s gravity field, it contributes to establishing a precise lunar reference frame and time system, enabling safer and more reliable navigation for spacecraft and surface operations,\u201d Park added.<\/p>\n
The same approach employed here using gravity data to assess the lunar interior, the researchers said, could be applied to other bodies in the solar system such as Saturn\u2019s moon Enceladus and Jupiter\u2019s moon Ganymede, two worlds of interest in the search for potential life beyond Earth.<\/p>\n
In the meantime, the new findings add to the understanding of Earth\u2019s eternal companion.<\/p>\n
\u201cThe moon plays a vital role in stabilizing Earth\u2019s rotation and generating ocean tides, which influence natural systems and daily rhythms,\u201d Park said. \u201cOur knowledge of the moon has expanded through human and robotic missions that have revealed details about its surface and interior, yet many questions about its deep structure and history remain. As our closest neighbor, the moon continues to be an important focus of scientific discovery.\u201d \u2014 Reuters<\/p>\n","protected":false},"excerpt":{"rendered":"WASHINGTON, May 16 \u2014 An exhaustive examination of lunar gravity using data obtained by two Nasa robotic spacecraft…\n","protected":false},"author":2,"featured_media":105180,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3844],"tags":[48299,1497,70,413,16,15],"class_list":{"0":"post-105179","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-lunar-gravity","9":"tag-moon","10":"tag-science","11":"tag-space","12":"tag-uk","13":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114515303161352268","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/105179","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=105179"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/105179\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/105180"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=105179"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=105179"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=105179"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}