{"id":3065,"date":"2019-04-22T16:38:05","date_gmt":"2019-04-22T13:38:05","guid":{"rendered":"http:\/\/energyholding.world\/?p=3065"},"modified":"2019-04-22T16:39:37","modified_gmt":"2019-04-22T13:39:37","slug":"nasas-cassini-reveals-surprises-with-titans-lakes","status":"publish","type":"post","link":"http:\/\/energyholding.world\/?p=3065","title":{"rendered":"NASA’s Cassini Reveals Surprises with Titan’s Lakes"},"content":{"rendered":"\n
\"\"

This near-infrared, color view from Cassini shows the sun glinting off of Titan’s north polar seas.
Credits: NASA\/JPL-Caltech\/Univ. Arizona\/Univ. Idaho
Full image and caption<\/a> <\/figcaption><\/figure><\/div>\n\n\n\n

On its final flyby of Saturn’s largest moon in 2017, NASA’s Cassini spacecraft gathered radar<\/a>\n data revealing that the small liquid lakes in Titan’s northern \nhemisphere are surprisingly deep, perched atop hills and filled with \nmethane.<\/p>\n\n\n\n

The new findings, published April 15 in Nature Astronomy, are the \nfirst confirmation of just how deep some of Titan’s lakes are (more than\n 300 feet, or 100 meters) and of their composition. They provide new \ninformation about the way liquid methane rains on, evaporates from and \nseeps into Titan \u2014 the only planetary body in our solar system other \nthan Earth known to have stable liquid on its surface.<\/p>\n\n\n\n

Scientists have known that Titan’s hydrologic cycle works similarly \nto Earth’s \u2014 with one major difference. Instead of water evaporating \nfrom seas, forming clouds and rain, Titan does it all with methane and \nethane. We tend to think of these hydrocarbons as a gas on Earth, unless\n they’re pressurized in a tank. But Titan is so cold that they behave as\n liquids, like gasoline at room temperature on our planet.<\/p>\n\n\n\n

Scientists have known that the much larger northern seas are filled \nwith methane, but finding the smaller northern lakes filled mostly with \nmethane was a surprise. Previously, Cassini data measured Ontario Lacus,\n the only major lake in Titan’s southern hemisphere. There they found a \nroughly equal mix of methane and ethane. Ethane is slightly heavier than\n methane, with more carbon and hydrogen atoms in its makeup.<\/p>\n\n\n\n

«Every time we make discoveries on Titan, Titan becomes more and more\n mysterious,» said lead author Marco Mastrogiuseppe, Cassini radar \nscientist at Caltech in Pasadena, California. «But these new \nmeasurements help give an answer to a few key questions. We can actually\n now better understand the hydrology of Titan.»<\/p>\n\n\n\n

Adding to the oddities of Titan, with its Earth-like features carved \nby exotic materials, is the fact that the hydrology on one side of the \nnorthern hemisphere is completely different than the that of other side,\n said Cassini scientist and co-author Jonathan Lunine of Cornell \nUniversity in Ithaca, New York.<\/p>\n\n\n\n

«It is as if you looked down on the Earth’s North Pole and could see \nthat North America had completely different geologic setting for bodies \nof liquid than Asia does,» Lunine said.<\/p>\n\n\n\n

On the eastern side of Titan, there are big seas with low elevation, \ncanyons and islands. On the western side: small lakes. And the new \nmeasurements show the lakes perched atop big hills and plateaus. The new\n radar measurements confirm earlier findings that the lakes are far above sea level<\/a>,\n but they conjure a new image of landforms \u2014 like mesas or buttes \u2014 \nsticking hundreds of feet above the surrounding landscape, with deep \nliquid lakes on top.<\/p>\n\n\n\n

The fact that these western lakes are small \u2014 just tens of miles \nacross \u2014 but very deep also tells scientists something new about their \ngeology: It’s the best evidence yet that they likely formed when the \nsurrounding bedrock of ice and solid organics chemically dissolved and \ncollapsed. On Earth, similar water lakes are known as karstic lakes. \nOccurring in in areas like Germany, Croatia and the United States, they \nform when water dissolves limestone bedrock.<\/p>\n\n\n\n

Alongside the investigation of deep lakes, a second paper in Nature \nAstronomy helps unravel more of the mystery of Titan’s hydrologic cycle.\n Researchers used Cassini data to reveal what they call transient lakes.\n Different sets of observations \u2014 from radar and infrared data \u2014 seem to\n show liquid levels significantly changed.<\/p>\n\n\n\n

The best explanation is that there was some seasonally driven change \nin the surface liquids, said lead author Shannon MacKenzie, planetary \nscientist at the Johns Hopkins Applied Physics Laboratory in Laurel, \nMaryland. «One possibility is that these transient features could have \nbeen shallower bodies of liquid that over the course of the season \nevaporated and infiltrated into the subsurface,» she said.<\/p>\n\n\n\n

These results and the findings from the Nature Astronomy paper on \nTitan’s deep lakes support the idea that hydrocarbon rain feeds the \nlakes, which then can evaporate back into the atmosphere or drain into \nthe subsurface, leaving reservoirs of liquid stored below.<\/p>\n\n\n\n

Cassini, which arrived in the Saturn system in 2004 and ended its \nmission in 2017 by deliberately plunging into Saturn’s atmosphere, \nmapped more than 620,000 square miles (1.6 million square kilometers) of\n liquid lakes and seas on Titan’s surface. It did the work with the \nradar instrument, which sent out radio waves and collected a return \nsignal (or echo) that provided information about the terrain and the \nliquid bodies’ depth and composition, along with two imaging systems \nthat could penetrate the moon’s thick atmospheric haze.<\/p>\n\n\n\n

The crucial data for the new research were gathered on Cassini’s \nfinal close flyby of Titan, on April 22, 2017. It was the mission’s last\n look at the moon’s smaller lakes, and the team made the most of it. \nCollecting echoes from the surfaces of small lakes while Cassini zipped \nby Titan was a unique challenge.<\/p>\n\n\n\n

«This was Cassini’s last hurrah at Titan, and it really was a feat,» Lunine said<\/p>\n\n\n\n

The Cassini-Huygens mission is a cooperative project of NASA, ESA \n(European Space Agency) and the Italian Space Agency. NASA’s Jet \nPropulsion Laboratory, a division of Caltech in Pasadena, California, \nmanages the mission for NASA’s Science Mission Directorate, Washington. \nJPL designed, developed and assembled the Cassini orbiter. The radar \ninstrument was built by JPL and the Italian Space Agency, working with \nteam members from the U.S. and several European countries.<\/p>\n\n\n\n

More information about Cassini can be found here:<\/p>\n\n\n\n

https:\/\/solarsystem.nasa.gov\/cassini<\/a><\/p>\n\n\n\n

https:\/\/www.nasa.gov\/feature\/jpl\/nasas-cassini-reveals-surprises-with-titans-lakes<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

On its final flyby of Saturn’s largest moon in 2017, NASA’s Cassini spacecraft gathered radar data revealing that the small liquid lakes in Titan’s northern hemisphere are surprisingly deep, perched atop hills and filled with methane. The new findings, published April 15 in Nature Astronomy, are the first confirmation of just how deep some of […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18],"tags":[],"_links":{"self":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts\/3065"}],"collection":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3065"}],"version-history":[{"count":3,"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts\/3065\/revisions"}],"predecessor-version":[{"id":3069,"href":"http:\/\/energyholding.world\/index.php?rest_route=\/wp\/v2\/posts\/3065\/revisions\/3069"}],"wp:attachment":[{"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3065"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/energyholding.world\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}