The US space agency says that the evidence is hard to argue, for example there is a strange influence on the Kuiper Belt, a region in the Solar System that lies around the orbit of Neptune. According to NASA, the strange influence came from the planet suspected of lurking from a distance.
It is estimated that this planet has 10 times the mass of the Earth, and its location 20 times farther than the distance between the Sun and Neptune, which in fact is the outermost planet in the solar system. So it is concluded that the temperature on the planet is very cold.
Astronomers need to prove the existence of a planet that NASA called Planet Nine. "There are five theories from the observational evidence that lead to the existence of Planet Nine," said Konstantin Batygin, planetary astrophysicist from Caltech who oversees the discovery.