'Ninth planet' may exist in solar system: US scientists
A previously unknown giant planet, nicknamed Planet Nine, may have been discovered lurking in the outer reaches of our solar system, US scientists announced on Wednesday.
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 by researchers at the California Institute of Technology (Caltech).
"In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the Sun."
The report was published in the Astronomical Journal.
Researchers Konstantin Batygin and Mike Brown say they found the planet through mathematical modeling and computer simulations, and have not yet observed the object directly.
The celestial body has about 5,000 times the mass of Pluto.
"This would be a real ninth planet," said Brown, a professor of planetary astronomy.
"It's a pretty substantial chunk of our solar system that's still out there to be found, which is pretty exciting."