The solar system appears to have a new ninth planet. Today, two scientists announced evidence that a body nearly the size of Neptune\u2014but as yet unseen\u2014orbits the sun every 15,000 years. During the solar system\u2019s infancy 4.5 billion years ago, they say, the giant planet was knocked out of the planet-forming region near the sun. Slowed down by gas, the planet settled into a distant elliptical orbit, where it still lurks today.<\/p>\n
The claim is the strongest yet in the centuries-long search for a \u201cPlanet X\u201d beyond Neptune. The quest has been plagued by far-fetched claims and even outright quackery. But the new evidence comes from a pair of respected planetary scientists, Konstantin Batygin and Mike Brown of the California Institute of Technology (Caltech) in Pasadena, who prepared for the inevitable skepticism with detailed analyses of the orbits of other distant objects and months of computer simulations. \u201cIf you say, \u2018We have evidence for Planet X,\u2019 almost any astronomer will say, \u2018This again? These guys are clearly crazy.\u2019 I would, too,\u201d Brown says. \u201cWhy is this different? This is different because this time we\u2019re right.\u201d<\/p>\n Mike Brown (left) and Konstantin Batygin.<\/p>\n LANCE HAYASHIDA\/CALTECH<\/p>\n<\/figcaption><\/figure>\n Outside scientists say their calculations stack up and express a mixture of caution and excitement about the result. \u201cI could not imagine a bigger deal if\u2014and of course that\u2019s a boldface \u2018if\u2019\u2014if it turns out to be right,\u201d says Gregory Laughlin, a planetary scientist at the University of California (UC), Santa Cruz. \u201cWhat\u2019s thrilling about it is [the planet] is detectable.\u201d<\/p>\n Batygin and Brown inferred its presence from the peculiar clustering of six previously known objects that orbit beyond Neptune. They say there\u2019s only a 0.007% chance, or about one in 15,000, that the clustering could be a coincidence. Instead, they say, a planet with the mass of 10 Earths has shepherded the six objects into their strange elliptical orbits, tilted out of the plane of the solar system.<\/p>\n The orbit of the inferred planet is similarly tilted, as well as stretched to distances that will explode previous conceptions of the solar system. Its closest approach to the sun is seven times farther than Neptune, or 200 astronomical units (AUs). (An AU is the distance between Earth and the sun, about 150 million kilometers.) And Planet X could roam as far as 600 to 1200 AU, well beyond the Kuiper belt, the region of small icy worlds that begins at Neptune\u2019s edge about 30 AU.<\/p>\n If Planet X is out there, Brown and Batygin say, astronomers ought to find more objects in telltale orbits, shaped by the pull of the hidden giant. But Brown knows that no one will really believe in the discovery until Planet X itself appears within a telescope viewfinder. \u201cUntil there\u2019s a direct detection, it\u2019s a hypothesis\u2014even a potentially very good hypothesis,\u201d he says. The team has time on the one large telescope in Hawaii that is suited for the search, and they hope other astronomers will join in the hunt.<\/p>\n Killing Pluto was fun, but this is head and shoulders above everything else.<\/p>\n![\"Mike](\"https:\/\/cosmicconvergence.org\/wp-content\/uploads\/2016\/01\/maxresdefault-2.jpg\")
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