Ninth planet may exist, say researchers
A NINTH planet larger than Earth could be hiding far beyond Pluto in the cold, dark depths of the solar system, according to two researchers at the California Institute of Technology (Caltech).
Nicknamed Planet Nine, the object "has a mass about 10 times that of Earth" and follows a "bizarre, highly elongated orbit in the distant solar system", said a statement on Wednesday from Caltech.
"In fact, it would take this new planet between 10,000 years and 20,000 years to make just one full orbit around the Sun."
The report was published in the University of Wisconsin's Astronomical Journal, reported Agence France-Presse.
Researchers Konstantin Batygin and Mike Brown said they have yet to observe the object directly but found it through mathematical modelling and computer simulations.
The presumed planet has about 5,000 times the mass of Pluto and scientists believe its gravity has affected the motion of dwarf planets in the outer solar system.
Essentially, celestial bodies are perturbed in the field of icy objects and debris beyond Neptune known as the Kuiper Belt.
Assistant Professor Batygin said: "For the first time in over 150 years, there is solid evidence that the solar system's planetary census is incomplete."
Said Professor Brown: "All those people who are mad that Pluto is no longer a planet can be thrilled to know that there is a real planet out there still to be found."
Prof Brown is well known for the role he played in demoting Pluto from a planet to a dwarf planet in 2006, reported China's Xinhua news agency.