{"id":19428,"date":"2016-03-21T21:08:11","date_gmt":"2016-03-21T13:08:11","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/ancient-pluto-could-have-had-rivers-and-lakes-of-liquid-nitrogen-scientists-say\/"},"modified":"2016-03-21T21:08:11","modified_gmt":"2016-03-21T13:08:11","slug":"ancient-pluto-could-have-had-rivers-and-lakes-of-liquid-nitrogen-scientists-say","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/ancient-pluto-could-have-had-rivers-and-lakes-of-liquid-nitrogen-scientists-say\/","title":{"rendered":"Ancient Pluto could have had rivers and lakes of liquid nitrogen, scientists say"},"content":{"rendered":"
\"Psychedelic
This enhanced color image of Pluto highlights the many subtle color differences between Pluto\u2019s distinct regions. The imagery was collected by the spacecraft\u2019s Ralph\/MVIC color camera on July 14, 2015, from a range of 22,000 miles. (Credit: NASA \/ JHUAPL \/ SwRI)<\/figcaption><\/figure>\n

Rivers and lakes of liquid nitrogen may have splashed over Pluto\u2019s surface hundreds of millions of years ago, and could do so again, due to shifts in the dwarf planet\u2019s orbit and the tilt of its orbit.<\/p>\n

That hypothesis is a good fit for the evidence collected last July when NASA\u2019s New Horizons spacecraft zoomed past the dwarf planet and its moons, scientists said today.<\/p>\n

Today\u2019s revelations came during a review of New Horizons\u2019 findings at the Lunar and Planetary Science Conference in The Woodlands, Texas. Research teams shared their latest findings about the mission, including some that have yet to be published in journals such as Icarus.<\/p>\n

\"pluto\"
\nScience journalist Alan Boyle<\/strong> is the author of “The Case for Pluto: How a Little Planet Made A Big Difference.”<\/p>\n

One team member, MIT\u2019s Richard Binzel, said the conditions conducive to creating a lake of liquid nitrogen might have existed 800 or 900 million years ago. During that epoch, Pluto\u2019s axial tilt was dramatic enough to expose a wide area of the distant world\u2019s surface to constant sunlight for long periods of time.<\/p>\n

\u201cIf you were to have a flyby at one of those epochs, millions or billions of years ago, you might have seen, for example, that lake reflecting sunlight specularly at you, because that surface is liquid rather than frozen as it is today,\u201d said mission principal investigator Alan Stern, a planetary scientist at the Southwest Research Institute, also known as SwRI.<\/p>\n

The phenomenon would explain modern-day features on Pluto that look as if they\u2019re lakes or rivers that have frozen in place.<\/p>\n

The \u201clakes on Pluto\u201d scenario emerges from computer models that run the sequence of shifts in Pluto\u2019s orbit and the tilt of its axis backward for billions of years. Binzel said those models suggest that Pluto is at an intermediate point between climate extremes.<\/p>\n

Today, Pluto\u2019s axis is tilted about 120 degrees, which is far more dramatic than Earth\u2019s 23-degree tilt. That means there\u2019s an overlap between Pluto\u2019s arctic zone, where the sun never sets during the planet\u2019s summer season; and its tropical zone, where the sun is directly overhead at some point in Pluto\u2019s orbit.<\/p>\n

\"Pluto's
Pluto\u2019s \u201ctropical arctic\u201d experiences both direct sunlight and prolonged periods of sunlight and darkness. (Credit: Richard Binzel and Alissa Earle \/ MIT, adapted from submission to Icarus)<\/figcaption><\/figure>\n

The models suggest that the axial tilt was even more extreme many millions of years ago, due to an astronomical phenomenon known as the Milankovich cycle. The same type of cycle is thought to have given rise to long-term climate shifts on Earth.<\/p>\n

On Pluto, the climate shifts would have affected the density of Pluto\u2019s nitrogen-rich atmosphere. Stern said the atmosphere in ancient times could have been denser than that of Mars. \u201cThis opens up the possibility that liquid nitrogen may have once or even many times flowed on Pluto\u2019s surface,\u201d he said.<\/p>\n

The researchers cautioned that New Horizons\u2019 readings were still being analyzed. The \u201clakes on Pluto\u201d scenario may have to be fine-tuned or discarded when more of the data comes back.<\/p>\n

\u201cWe are just beginning to understand the long-term climate of Pluto,\u201d Binzel said.<\/p>\n

Stern said about half of the data remained to be downlinked from the spacecraft, which is now more than 180 million miles beyond Pluto.<\/p>\n

Among other findings reported at the conference today:<\/p>\n

    \n
  • Binzel said the orbital shifts could also explain why most of Pluto\u2019s equatorial region is covered with a reddish layer of nitrogen-containing compounds known as tholins. More of the ice may have been cooked out of that region by heightened exposure to sunlight for billions of years. The bright, icy region known informally as Sputnik Planum is an exception. That region\u2019s ice was apparently trapped in a huge impact crater, Binzel said.<\/li>\n
  • Pluto\u2019s surface shows extensive evidence of glacial flow and erosion. \u201cThere are two likely scenarios for the erosion we see,\u201d Orkan Umurhan, a researcher at NASA\u2019s Ames Research Center, said in a statement. \u201cIt could be gradual, when much of Pluto\u2019s nitrogen ice was lost over time. Or it could be part of a cycle in which the nitrogen ice evaporates and redeposits on the highlands before flowing back into the plains. In all likelihood, both scenarios have been and still are operating.\u201d<\/li>\n
  • A study of the size and the number of craters on Pluto and its moons suggests the satellite system was created in a giant impact between Pluto and another celestial object about 4 billion years ago. \u201cThis is our first proof that the giant impact that created the Pluto system must have been ancient, not recent,\u201d SwRI researcher Kelsi Singer said in a statement. \u201cThat puts the impact on a timeline going back billions of years, rather than millions.\u201d<\/li>\n<\/ul>\n

    Stern will deliver a public lecture titled \u201cThe Exploration of Pluto\u201d at 5:30 p.m. PT Tuesday.  The lecture will be archived online. For the full schedule of LPSC\u2019s live and archived Web events, see http:\/\/livestream.com\/viewnow\/LPSC2016.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

    This enhanced color image of Pluto highlights the many subtle color differences between Pluto\u2019s distinct regions. The imagery was collected by the spacecraft\u2019s Ralph\/MVIC color camera on July 14, 2015, from a range of 22,000 miles. (Credit: NASA \/ JHUAPL \/ SwRI) Rivers and lakes of liquid nitrogen may have splashed over Pluto\u2019s surface hundreds of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[4809,2174,4810,2848],"class_list":["post-19428","post","type-post","status-publish","format-standard","hentry","category-news","tag-nasa-new-horizons","tag-new-horizons","tag-new-horizons-probe","tag-pluto"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/19428"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=19428"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/19428\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=19428"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=19428"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=19428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}