{"id":6911,"date":"2022-01-26T18:01:06","date_gmt":"2022-01-26T18:01:06","guid":{"rendered":"https:\/\/mailinvest.blog\/index.php\/2022\/01\/26\/turns-out-there-was-no-lake-at-mars-south-pole-after-all\/"},"modified":"2022-01-26T18:01:06","modified_gmt":"2022-01-26T18:01:06","slug":"turns-out-there-was-no-lake-at-mars-south-pole-after-all","status":"publish","type":"post","link":"https:\/\/mailinvest.blog\/index.php\/2022\/01\/26\/turns-out-there-was-no-lake-at-mars-south-pole-after-all\/","title":{"rendered":"Turns Out There Was No Lake at Mars’ South Pole After All"},"content":{"rendered":"

<\/a>\n<\/p>\n

This site may earn affiliate commissions from the links on this page. Terms of use<\/a>.<\/div>\n
\n
\n
\n \t \t \"Mars<\/div>\n<\/p><\/div>\n

Sadly, after further analysis, it appears that the briny subsurface \u2018lake\u2019 researchers reported at Mars\u2019 south pole is much more likely to be a huge mass of volcanic rock.<\/p>\n

In 2018, European Space Agency (ESA) researchers reported signs suggesting the presence of a mass of liquid water at the planet\u2019s south pole. There was a bright patch on the Mars Express orbiter\u2019s radar that didn\u2019t seem to belong; the researchers interpreted it as a twenty-kilometer-wide lake. But the reports weren\u2019t a slam dunk. It\u2019s tough to square the presence of liquid water with what we know about conditions on Mars. For one thing, in the extremely thin Martian atmosphere<\/a>, it\u2019s easy for ice to sublimate away. So easy, in fact, that Mars\u2019 north polar ice cap is seasonal \u2014 it\u2019s formed and destroyed each year by sublimation. Furthermore, at Martian temperatures, fresh water would long since have frozen. But if the MARSIS<\/a> (Mars Advanced Radar for Subsurface and Ionosphere Sounding) readings didn\u2019t indicate water, what did<\/em> they indicate?<\/p>\n

\"There<\/a><\/p>\n

Ancient Mars may have had enough water to form oceans that covered a third of its surface. Based on geological data, this artist\u2019s impression shows what those oceans might have looked like. Image by Ittiz, CC BY-SA 3.0<\/p>\n<\/div>\n

Even if we had a rover down there, we wouldn\u2019t be able to take samples to confirm or correct the lake hypothesis, because the bright patch at Mars\u2019 south pole is buried under almost a mile of ice. So, Dr. Cyril Grima and colleagues ran a simulation of what the surface of Mars would look like entirely<\/em> buried under the same amount of ice. Lo and behold, a bunch of the same bright patches popped up \u2014 but many of them were directly atop known volcanic plains, a kind of terrain created by lava flows.<\/p>\n

Water Isn\u2019t Always Wet<\/h3>\n

\u201cWe do not understand how liquid water could be there, because we wouldn\u2019t expect to have enough energy and pressure to melt water there, even if the water is salty,\u201d said Grima, corresponding author of a new analysis<\/a> of the 2018 findings. There\u2019s water ice on Mars, and water sequestered in Martian bedrock. But in the ice-sheet simulation, neither produced the right radar signature. What did? Volcanic plains. These broad, flat, iron-rich Martian lava flows occur all over the planet\u2019s surface.<\/p>\n

\u201cMars is known to have these terrains all over the planet, so it\u2019s far more likely to have this terrain under the ice than liquid water,\u201d says Grima. \u201cWe aren\u2019t ruling out this water, but it\u2019s lowering by far the likelihood that it\u2019s there.\u201d<\/p>\n

We\u2019ve been hunting for water on Mars for decades, with varying success. Mostly, we\u2019ve found ice. Finding a lake at Mars\u2019 south pole would have been incredible. But lake or no lake, scientists aren\u2019t giving up hope. NASA\u2019s Perseverance rover is in Mars\u2019 Jezero Crater, hunting for signs of ancient life. Water is life, here on Earth \u2014 so we\u2019re looking for it on Mars.<\/p>\n

Clay at the bottom of the crater indicates that Jezero once held a crater lake. That lake was fed by a river, whose delta opens up into a formation called Three Forks, on the northwestern edge of the crater. From orbit, it looks like the delta is full of boulders. How did they end up there? On Earth, it takes a decent-sized flood to lift and carry rocks that big. Forthcoming images and data from Perseverance\u2019s RIMFAX, SHERLOC and WATSON instruments will help us learn more about just how wet ancient Mars might have been.<\/span><\/p>\n

Now Read<\/strong>:<\/p>\n

\u00a0<\/p>\n<\/p><\/div>\n