Far Beats

Planet Nine is a hypothetical large planet in the far outer Solar System, the gravitational affects of which would explain the unusual orbital configuration of a group of trans-Neptunian objects (TNOs) that orbit mostly beyond the Kuiper belt. The hypothesis first took form in a 2014 letter to the journal Nature by astronomers Chad Trujillo and Scott S. Sheppard, who had inferred the possible existence of a massive planet from similarities in the orbits of the distant trans-Neptunian objects Sedna and 2012 VP113. On 20 January 2016, researchers Konstantin Batygin and Michael E. Brown at Caltech argued that a massive outer planet would be the likeliest explanation for the similarities in orbits of six distant objects. The predicted planet would be a super-Earth, with an estimated mass of about 10 times that of Earth (approximately 5,000 times the mass of Pluto), a diameter two to four times that of Earth, and a highly elliptical orbit that is so far away that it could take around 15,000 years to orbit the Sun