In January 2015, Caltech (California Institute of Technology) astronomers Konstantin Batygin and Michael E. Brown published an article titled Evidence For A Distant Giant Planet In The Solar System and announced calculation-based evidence of a massive ninth planet. Despite they have had started their research to demonstrate that there’s no ninth planet, they reached the exact opposite result: there must be a ninth planet beyond Pluto, and it’s probably 10 times the mass of Earth (for comparison, Neptune has 17 times as much mass compared to the Earth).

In an effort to state Planet Nine’s exact location, a team of French scientists used the data from the Cassini–Huygens (an unmanned spacecraft orbiting Saturn, launched on October 15, 1997). They couldn’t able to find the exact location of the giant planet, but they narrowed down the “possible areas”.