International space agency NASA in October 2017 revealed that a mysterious world called Planet Nine does exist in the solar system.
The Planet Nine might be lingering on the icy outer edges of the solar system hiding in the dark, but stretching out the orbits of distant bodies.
It is extremely distant and is 10 times the mass of Earth and 20 times farther from the sun than Neptune.
There are five different lines of observational evidence pointing to the existence of Planet Nine. These 5 evidences are:
• Firstly, six known objects in the distant Kuiper Belt, a region of icy bodies stretching from Neptune towards interstellar space, all have elliptical orbits pointing in the same direction.
• Secondly, these orbits are tilted the same way, about 30 degrees downward compared to the pancake-like plane within which the planets orbit the sun.
• Thirdly, computer simulations of solar system with Planet Nine show that there should be more objects tilted with respect to the solar plane and the tilt would be on the order of 90 degrees, as if the plane of the solar system and these objects formed an "X" when viewed edge-on.
• Fourthly, Planet Nine could have tilted the planets of our solar system during the last 4.5 billion years.
• Last but not least, the telltale sign of Planet Nine's presence involves objects from the Kuiper Belt that orbit in the opposite direction in the solar system. Planet Nine's orbital influence would explain why these bodies from the distant Kuiper Belt end up polluting the inner Kuiper Belt.
The remaining step is to find Planet Nine itself. The NASA scientists are using the Subaru Telescope at Mauna Kea Observatory in Hawaii to find out extremely distant objects lost in huge swaths of sky.
If discovered, Planet Nine could turn out to be the missing super Earth- a planet with a mass higher than the Earth’s, but substantially lower than the masses of ice giants Uranus and Neptune.