The ninth planet is referred as planet x. The researchers found a mathematical evidence. And according to it there may be a “planet x” deep in our solar system. This hypothetical planet is beyond Pluto. The orbit of this planet is highly elongated more than Pluto. According to the evidence this planet is about the size of Neptune. This planet could have 10 times more mass than earth. It may take 10000 to 20000 Earth years for the planet to orbit around the sun. This planet is farther from the sun beyond Neptune.
This planet has not yet been discovered. Hence, there is a debate in the community for its existence. According to the mathematical evidence it exists. Now, astronomers are searching for this predicted planet. In the year 2015, Caltech astronomer Konstantin Batygin and Mike Brown, put forth the evidence of giant planet tracing an unusual elongated orbit. This prediction is based on the mathematical model and computer simulation.
The existence of this planet is currently theoretical, no direct observations of the planet are made. This mathematical predictions could explain the orbits of some smaller objects in the Kuiper belt. The Kuiper belt is also called as Edgeworth-Kuiper belt. The Kuiper belt is a disc like structure in the outer solar system. It is similar to the asteroid belt present in between Mars and Jupiter, but it is 20 times wide and 200 times massive. This belt is in the outer solar system and it extends far beyond the orbit of Neptune. Astronomers studied this Kuiper Belt and they noticed some dwarf planets and icy objects that tends to follow the orbits in cluster. Later by analyzing the orbits they predicted that there maybe a planet beyond Pluto.