Two leading US astronomers have published evidence that the solar system contains a new ninth planet, which takes up to 20,000 years to make one full orbit around the sun.
Konstantin Batygin and Mike Brown of the California Institute of Technology say their proposed “Planet Nine” has a mass about 10 times that of Earth and a bizarre and highly elongated orbit much further out than Pluto. The demotion of Pluto from its planetary status 10 years ago left the solar system with eight planets.
The researchers identified Planet Nine’s existence through mathematical modelling and computer simulations, described in the Astronomical Journal. No one has observed it directly, yet.
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