{"id":19492,"date":"2016-01-20T17:28:16","date_gmt":"2016-01-20T09:28:16","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/planet-nine-astronomers-boost-the-case-for-a-large-unseen-planet-x\/"},"modified":"2016-01-20T17:28:16","modified_gmt":"2016-01-20T09:28:16","slug":"planet-nine-astronomers-boost-the-case-for-a-large-unseen-planet-x","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/planet-nine-astronomers-boost-the-case-for-a-large-unseen-planet-x\/","title":{"rendered":"\u2018Planet Nine\u2019? Astronomers boost the case for a large, unseen Planet X"},"content":{"rendered":"<figure id=\"attachment_224038\" aria-describedby=\"caption-attachment-224038\" style=\"width: 630px\" class=\"wp-caption aligncenter\"><img fetchpriority=\"high\" decoding=\"async\" class=\"size-full-width wp-image-224038\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet-630x375.jpg\" alt=\"Image: Distant planet\" width=\"630\" height=\"375\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet-630x375.jpg 630w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet-768x457.jpg 768w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet-1240x739.jpg 1240w\" sizes=\"(max-width: 630px) 100vw, 630px\"><figcaption data-nosnippet=\"\" id=\"caption-attachment-224038\" class=\"wp-caption-text\">An artist\u2019s conception shows a \u201csuper-Earth\u201d planet far from the sun. (Credit: R. Hurt \/ IPAC \/ Caltech)<\/figcaption><\/figure>\n<p>For decades, astronomers have gone back and forth over whether a \u201cPlanet X\u201d exists on the edge of our solar system&nbsp;\u2013 and now two researchers have laid out new evidence supporting the claim, including a rough idea of where it could be found.<\/p>\n<p>One of the most notable things about the claim has to do with one of the people who\u2019s making it: Mike Brown, the Caltech astronomer who says he \u201ckilled\u201d Pluto when it was the ninth planet.<\/p>\n<p>\u201cThis would be a real ninth planet,\u201d Brown said in a news release. \u201cThere have only been two true planets discovered since ancient times, and this would be the third.\u201d<\/p>\n<p>Brown\u2019s \u201ctwo true planets\u201d refer to Uranus and Neptune, not Pluto. To emphasize the point, Brown and his collaborator at Caltech, Konstantin Batygin, have nicknamed the object \u201cPlanet Nine.\u201d (Other nicknames are said to include George, Planet of the Apes, Jehoshaphat and Phattie.)<\/p>\n<p>There\u2019s one big gap in the argument: No such object has yet been detected. Instead, Brown and Batygin make the claim on the basis of a detailed analysis of objects that have been scattered into strange orbits in the Kuiper Belt. That\u2019s the broad ring of icy material that lies beyond the orbit of Neptune.<\/p>\n<p>The astronomers lay out their evidence in a paper published today by the Astrophysical Journal.<\/p>\n<p><iframe title=\"Evidence of a Ninth Planet\" src=\"https:\/\/www.youtube.com\/embed\/6poHQ2h00ZA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen=\"\" data-ratio=\"0.5625\" data-width=\"800\" data-height=\"450\" style=\"display: block; margin: 0px; width: 800px; height: 450px;\"><\/iframe><\/p>\n<p>\u201cAlthough we were initially quite skeptical that this planet could exist, as we continued to investigate its orbit and what it would mean for the outer solar system, we became increasingly convinced that it is out there,\u201d Batygin said.<\/p>\n<p>The proposed planet would have a mass about 10 times that of Earth, and should trace an eccentric orbit coming no closer to the sun than, say, 19 billion miles (200 astronomical units, where 1 AU equals the distance from Earth to the sun). In comparison, Neptune and Pluto come no closer than 30 AU. It would take 10,000 to 20,000 years for the proposed planet to make a full orbit of the sun.<\/p>\n<p><span class=\"icon-quotes-left\"><\/span>&nbsp;This is about the fifth or 10th prediction like this. \u2026 Not one has panned out.<span class=\"icon-quotes-right\"><\/span><\/p>\n<p>Batygin and Brown are by no means the first to predict the existence of a large world on the solar system\u2019s edge. Such claims have repeatedly been raised&nbsp;over the course of more than 30 years.<\/p>\n<p>\u201cThis is about the fifth or 10th prediction like this. \u2026 Not one has panned out,\u201d said Alan Stern, a planetary scientist at the Southwest Research Institute who is the principal investigator for NASA\u2019s New Horizons mission to Pluto and beyond.<\/p>\n<p>The new evidence focuses on the orbits of six distant objects that had previously been detected in the Kuiper Belt. The orbits are hard to explain, based on the gravitational interactions of the solar system\u2019s large planets.<\/p>\n<p>Batygin and Brown noticed that the long axes of the orbits all pointed in roughly the same direction, and that the orbits all had the roughly same tilt with respect to the solar system\u2019s main planetary plane.&nbsp;When they ran the numbers, the astronomers found the probability of such an arrangement occurring by chance was about 0.007 percent.<\/p>\n<p>The astronomers were able to tweak their orbital simulations to produce the arrangement if they added a large, distant planet with an \u201canti-aligned\u201d orbit. That means the point of the planet\u2019s closest approach to the sun would have to be placed diametrically opposite to the point of closest approach for the other six objects.<\/p>\n<figure id=\"attachment_224048\" aria-describedby=\"caption-attachment-224048\" style=\"width: 630px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full-width wp-image-224048\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet2-630x354.jpg\" alt=\"Kuiper Belt objects\" width=\"630\" height=\"354\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet2-630x354.jpg 630w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet2-768x432.jpg 768w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2016\/01\/160120-planet2-1240x698.jpg 1240w\" sizes=\"(max-width: 630px) 100vw, 630px\"><figcaption data-nosnippet=\"\" id=\"caption-attachment-224048\" class=\"wp-caption-text\">The orbits of six distant objects in the solar system point roughly in the same direction. Moreover, the orbits have a similar tilt with respect to the solar system\u2019s main plane. Astronomers say the gravitational influence of a world they call \u201cPlanet Nine\u201d provides the best explanation for the effect. This diagram was created using WorldWide Telescope. (Credit: R. Hurt \/ IPAC \/ Caltech)<\/figcaption><\/figure>\n<p>\u201cPlanet Nine\u201d could explain the seemingly puzzling orbits traced by two of the distant worlds, known as Sedna and 2012 VP113 (which has been nicknamed \u201cPlanet Biden\u201d in homage to a different kind of VP). What\u2019s more, the planet should kick still other objects into orbits in perpendicular planes. That matches observations made in just the last three years.<\/p>\n<p>\u201cWhen the simulation aligned the distant Kuiper Belt objects and created objects like Sedna, we thought this is kind of awesome&nbsp;\u2013 you kill two birds with one stone,\u201d Batygin said. \u201cBut with the existence of the planet also explaining these perpendicular orbits, not only do you kill two birds, you also take down a bird that you didn\u2019t realize was sitting in a nearby tree.\u201d<\/p>\n<p>Brown and Batygin suggest that the unseen world coalesced along with the solar system\u2019s four known giant planets&nbsp;\u2013 Jupiter, Saturn, Uranus and Neptune&nbsp;\u2013 and that it was kicked out into a stable but more distant orbit through gravitational interactions.<\/p>\n<p><span class=\"icon-quotes-left\"><\/span>&nbsp;I would love to find it. But I\u2019d also be perfectly happy if someone else found it.<span class=\"icon-quotes-right\"><\/span><\/p>\n<p>The simulation provides a rough idea of the planet\u2019s orbital track, but it can\u2019t point to where the planet currently lies on that track. If it\u2019s in the farthest reaches of its orbit, it would be so dim that only the world\u2019s largest telescopes could possibly see it. But if it\u2019s around the point of closest approach to the sun, there\u2019s a much better chance of spotting it. It might even show up in&nbsp;archived imagery.<\/p>\n<p>\u201cI would love to find it,\u201d Brown said. \u201cBut I\u2019d also be perfectly happy if someone else found it. That\u2019s why we\u2019re publishing this paper. We hope that other people are going to get inspired and start searching.\u201d<\/p>\n<p>Although the paper is certain&nbsp;to revive the search for&nbsp;Planet X, success is not certain: Previous surveys have failed to detect any Saturn-sized planets going out as far as 10,000 AU. Brown and Batygin say the planet they propose would be too small and dim to show up in those&nbsp;surveys.<\/p>\n<p>Considering Brown\u2019s history with Pluto, would Planet Nine fit his conception of a planet? Brown says it would, because the simulations indicate it would dominate the gravitational dynamics&nbsp;for a region of the solar system. The fact that it could affect the orbits of other objects over such a wide area would make it \u201cthe most planet-y of the planets in the whole solar system,\u201d Brown argued.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\" size-full wp-image-188079 alignleft\" src=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2015\/07\/pluto1.png\" alt=\"pluto\" width=\"250\" height=\"189\" srcset=\"https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2015\/07\/pluto1.png 250w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2015\/07\/pluto1-200x151.png 200w, https:\/\/cdn.geekwire.com\/wp-content\/uploads\/2015\/07\/pluto1-132x100.png 132w\" sizes=\"auto, (max-width: 250px) 100vw, 250px\"><br \/>\n<strong>Science journalist Alan Boyle<\/strong>&nbsp;is the author of &#8220;The Case for Pluto: How a Little Planet Made A Big Difference.&#8221;<\/p>\n<p>If the world is detected, it would put the International Astronomical Union\u2019s nearly 10-year-old definition of planethood to a new test. That definition put Pluto and other objects in a category known as dwarf planets, because they were deemed not to have \u201ccleared the neighborhood around its orbit.\u201d<\/p>\n<p>If Planet Nine is found, would the IAU declare that it\u2019s cleared out&nbsp;a&nbsp;celestial neighborhood ranging from the Kuiper Belt to the comet-filled Oort Cloud that lies beyond?&nbsp;Stern, who\u2019s a sharp critic of the IAU definition, says such an object could lead to a fresh round of rethinking.<\/p>\n<p>\u201cIf they do find it, it\u2019ll be more like Number 19, not Number 9,\u201d he told GeekWire in an email. \u201cAnd if it is found, it\u2019ll confirm lots of work predicting the Oort Cloud is littered with planets, and the solar system made dozens to hundreds of them.\u201d<\/p>\n<p>No matter how the search for Planet Nine turns out, Pluto\u2019s devotees and detractors can now agree on one thing, at least: The solar system is more complicated than astronomers thought, back when Pluto was the ninth planet.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>An artist\u2019s conception shows a \u201csuper-Earth\u201d planet far from the sun. (Credit: R. Hurt \/ IPAC \/ Caltech) For decades, astronomers have gone back and forth over whether a \u201cPlanet X\u201d exists on the edge of our solar system&nbsp;\u2013 and now two researchers have laid out new evidence supporting the claim, including a rough idea [&hellip;]<\/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":[1661,2840,5103,5104,4709,2848],"class_list":["post-19492","post","type-post","status-publish","format-standard","hentry","category-news","tag-astronomy","tag-dwarf-planets","tag-planet-nine","tag-planet-x","tag-planets","tag-pluto"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/19492"}],"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=19492"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/19492\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=19492"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=19492"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=19492"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}