{"id":8218,"date":"2022-01-25T14:59:28","date_gmt":"2022-01-25T19:59:28","guid":{"rendered":"https:\/\/spaceandplanetarynewswire.com\/?p=8218"},"modified":"2022-01-25T14:59:28","modified_gmt":"2022-01-25T19:59:28","slug":"hope-for-present-day-martian-groundwater-dries-up","status":"publish","type":"post","link":"https:\/\/spaceandplanetarynewswire.com\/?p=8218","title":{"rendered":"Hope for Present-Day Martian Groundwater Dries Up"},"content":{"rendered":"
A view of Mars\u2019 south pole. Research led by The University of Texas at Austin found that a 2018 discovery of liquid water under the Red Planet\u2019s south polar cap is most likely just radar reflecting from volcanic rock.<\/figcaption><\/figure>\n

Liquid water previously detected under Mars\u2019 ice-covered south pole is probably just a dusty mirage, according to a new study of the red planet led by researchers at The University of Texas at Austin.<\/p>\n

Scientists in 2018 had thought they were looking at liquid water when they saw bright radar reflections under the polar cap. However, the new study published Jan. 24<\/a> in the journal Geophysical Research Letters<\/em> found that the reflections matched those of volcanic plains found all over the red planet\u2019s surface. <\/p>\n

The researchers think their conclusion \u2014 volcanic rock buried under ice \u2014 is a more plausible explanation for the 2018 discovery, which was already in question after scientists calculated the unlikely conditions needed to keep water in a liquid state at Mars\u2019 cold, arid south pole.<\/p>\n

\u201cFor water to be sustained this close to the surface, you need both a very salty environment and a strong, locally generated heat source, but that doesn\u2019t match what we know of this region,\u201d said the study\u2019s lead author, Cyril Grima, a planetary scientist at the University of Texas Institute for Geophysics (UTIG). <\/p>\n

The south polar mirage dissolved when Grima added an imaginary global ice sheet across a radar map of Mars. The imaginary ice showed how Mars\u2019 terrains would appear when looked at through a mile of ice, allowing scientists to compare features across the entire planet with those under the polar cap.<\/p>\n

Grima noticed bright reflections, just like those seen in the south pole but scattered across all latitudes. In as many as could be confirmed, they matched the location of volcanic plains.<\/p>\n

On Earth, iron-rich lava flows can leave behind rocks that reflect radar in a similar way. Other possibilities include mineral deposits in dried riverbeds. Either way, Grima said, figuring out what they are could answer important questions about Mars\u2019 history.<\/p>\n

Although there may not be liquid water trapped under the southern polar cap, there is plenty of water ice on Mars, including in the thick polar caps. In fact, the new study hints at Mars\u2019 wetter past. <\/p>\n

Isaac Smith, a Mars geophysicist at York University, believes the bright radar signatures are a kind of clay made when rock erodes in water. In 2021, Smith, who was not part of either study, found that Earth-based clays reflected radar brightly, just like the bright spots in the 2018 south pole study.<\/p>\n

\u201cI think the beauty of Grima\u2019s finding is that while it knocks down the idea there might be liquid water under the planet\u2019s south pole today, it also gives us really precise places to go look for evidence of ancient lakes and riverbeds and test hypotheses about the wider drying out of Mars\u2019 climate over billions of years,\u201d he said.<\/p>\n

Grima\u2019s map is based on three years of data from MARSIS, a radar instrument launched in 2005 aboard the European Space Agency\u2019s Mars Express that has accumulated tremendous amounts of information about Mars. Grima and co-author J\u00e9r\u00e9mie Mouginot, a research scientist at the Institute of Environmental Geosciences in Grenoble, France, plan to dig further into the data to see what else MARSIS can turn up about Mars. <\/p>\n

For Smith, the study is a sobering lesson on the scientific process that is as relevant to Earth as it is to Mars.<\/p>\n

\u201cScience isn\u2019t foolproof on the first try,\u201d said Smith, who is an alumnus of the Jackson School of Geosciences at UT Austin. \u201cThat\u2019s especially true in planetary science where we\u2019re looking at places no one\u2019s ever visited and relying on instruments that sense everything remotely.\u201d<\/p>\n

Grima and Smith are now working on proposed missions to find water on Mars with radar, both as a resource for future human landing sites and to search for signs of past life.<\/p>\n","protected":false},"excerpt":{"rendered":"

Liquid water previously detected under Mars\u2019 ice-covered south pole is probably just a dusty mirage, according to a new study of the red planet led by researchers at The University of Texas at Austin. Scientists in 2018 had thought they were looking at liquid water when they saw bright radar reflections under the polar cap.…<\/p>\n","protected":false},"author":71,"featured_media":8220,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"fifu_image_url":"https:\/\/earimediaprodweb.azurewebsites.net\/Api\/v1\/Multimedia\/ca27069f-ebb6-48b1-a717-79bbc33a362c\/Rendition\/low-res\/Content\/Public","fifu_image_alt":"Hope for Present-Day Martian Groundwater Dries Up","footnotes":""},"categories":[207],"tags":[],"class_list":["post-8218","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\/8218","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=8218"}],"version-history":[{"count":1,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8218\/revisions"}],"predecessor-version":[{"id":8219,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8218\/revisions\/8219"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/media\/8220"}],"wp:attachment":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8218"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8218"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}