Free Astronomy Magazine March-April 2016

PLANETOLOGY tech researchers reduced the sample of KBOs on which to further study the orbits and selected from the Trujillo and Shep- pard’s list consisting of a dozen objects, the 6 more distant from the Sun (perihelia be- yond the orbit of Neptune and semi-major axis greater than 150 AU): thus Sedna, 2012 VP 113 , 2004 VN 112 , 2007 TG 422 , 2010 GB 174 and 2013 RF 98 , which more than others should be affected by the influ- ence of the hypotheti- cal planet. All 6 were discovered with differ- ent telescopes in dif- ferent surveys, which ruled out any possible biases introduced by the methods used by the discoverers. With this in mind, in 2015 Batygin started a series of complex sim- ulations of the solar system by adding a vir- tual planet of various masses and located on different orbits, to ver- ify which version was capable of more faith- Sun and next to the ecliptic, but also phys- ically clustered in space, with their orbits facing the same direction and all tilted about 30 degrees. In order to implement sustainable simula- tions (lasting several months even with the most powerful computers), the two Cal- T he orbits of the 6 most dis- tant KBOs of the solar system ap- pear unusually aligned in similar directions and, if viewed edge- wise, also tilted in the same way. This particular configuration can be explained by admitting the ex- istence of a plan- et of about 10 Earth masses, moving in an orbit similar to the one drawn here. In the diagram below were added the perpendicular orbits predicted by the simulations and observed for 5 real objects. [Caltech/R. Hurt (IPAC)]