{"id":9249,"date":"2024-06-09T14:40:55","date_gmt":"2024-06-09T18:40:55","guid":{"rendered":"https:\/\/spaceandplanetarynewswire.com\/?p=9249"},"modified":"2024-06-09T14:40:55","modified_gmt":"2024-06-09T18:40:55","slug":"new-research-finds-lake-under-mars-ice-cap-unlikely","status":"publish","type":"post","link":"https:\/\/spaceandplanetarynewswire.com\/?p=9249","title":{"rendered":"New Research Finds Lake Under Mars Ice Cap Unlikely"},"content":{"rendered":"
This image taken by NASA\u2019s Mars Reconnaissance Orbiter shows ice sheets at Mars\u2019 south pole. Credit: NASA\/JPL-Caltech\/University of Arizona\/JHU<\/figcaption><\/figure>\n

Cornell University researchers have provided a simple and comprehensive \u2013 if less dramatic \u2013 explanation for bright radar reflections initially interpreted as liquid water beneath the ice cap on Mars\u2019 south pole.<\/p>\n

Their simulations show that small variations in layers of water ice \u2013 too subtle for ground-penetrating radar instruments to resolve \u2013 can cause constructive interference between radar waves. Such interference can produce reflections whose intensity and variability match observations to date \u2013 not only in the area proposed to be liquid water, but across the so-called south polar layered deposits.<\/p>\n

\u201c<\/strong>I can\u2019t say it\u2019s impossible that there\u2019s liquid water down there, but we\u2019re showing that there are much simpler ways to get the same observation without having to stretch that far, using mechanisms and materials that we already know exist there,\u201d said Daniel Lalich<\/a>, research associate in the Cornell Center for Astrophysics and Planetary Science. \u201cJust through random chance you can create the same observed signal in the radar.\u201d<\/p>\n

Lalich is the first author of \u201cSmall Variations in Ice Composition and Layer Thickness Explain Bright Reflections Below Martian Polar Cap Without Liquid Water<\/a>,\u201d published June 7 in Science Advances.<\/em><\/p>\n

Robotic explorers have provided extensive evidence that water flowed on the surface of ancient Mars, including at a former river delta now under investigation by NASA\u2019s Perseverance rover. Relying on a radar instrument that can probe below the surface to detect water ice and potentially hidden aquifers, members of the European Space Agency-led Mars Express orbiter\u2019s science team in 2018 announced<\/a> they\u2019d discovered a lake buried below the south polar cap.<\/p>\n

The implications were enormous: Where there is liquid water, there could be microbial life.<\/p>\n

But while the same bright radar reflections would likely indicate a subglacial lake on Earth, Lalich said, the temperature and pressure conditions on Mars are very different.<\/p>\n

Using simpler models, Lalich previously showed<\/a> that the bright radar signals could be created in the absence of liquid water, but he said assumptions about layers of frozen carbon dioxide below the ice cap likely were incorrect.<\/p>\n

The new research tells a more complete story, he said, closing gaps in the radar interference hypothesis with more realistic modeling. The thousands of randomly generated layering scenarios were based only on conditions known to exist at the Martian poles, and varied the ice layers\u2019 composition and spacing in ways that would be expected over tens or hundreds of miles.<\/p>\n

Those slight adjustments sometimes produced bright subsurface signals consistent with observations in each of the three frequencies used by the Mars Express orbiter\u2019s MARSIS radar instrument, a partnership between NASA and the Italian Space Agency. Likely for a simple reason, Lalich argues: Radar waves bouncing off layers spaced too closely for the instrument to resolve may be combined, amplifying their peaks and troughs.<\/p>\n

\u201cThis is the first time we have a hypothesis that explains the entire population of observations below the ice cap, without having to introduce anything unique or odd,\u201d Lalich said. \u201cThis result where we get bright reflections scattered all over the place is exactly what you would expect from thin-layer interference in the radar.\u201d<\/p>\n

While not ruling out the potential for some future detection by more capable instruments, Lalich said he suspects the story of liquid water and potential life on the red planet ended long ago.<\/p>\n

\u201cThe idea that there would be liquid water even somewhat near the surface would have been really exciting,\u201d Lalich said. \u201cI just don\u2019t think it\u2019s there.\u201d<\/p>\n

The research was supported by NASA.<\/p>\n","protected":false},"excerpt":{"rendered":"

Cornell University researchers have provided a simple and comprehensive \u2013 if less dramatic \u2013 explanation for bright radar reflections initially interpreted as liquid water beneath the ice cap on Mars\u2019 south pole. Their simulations show that small variations in layers of water ice \u2013 too subtle for ground-penetrating radar instruments to resolve \u2013 can cause…<\/p>\n","protected":false},"author":71,"featured_media":9250,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"fifu_image_url":"https:\/\/www.techexplorist.com\/wp-content\/uploads\/2024\/06\/Mars-south-pole.jpg","fifu_image_alt":"Auto Draft","footnotes":""},"categories":[207],"tags":[],"class_list":["post-9249","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"_links":{"self":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/9249","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/users\/71"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=9249"}],"version-history":[{"count":1,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/9249\/revisions"}],"predecessor-version":[{"id":9251,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/9249\/revisions\/9251"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/media\/9250"}],"wp:attachment":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9249"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9249"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9249"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}