Scientists discover possible location of ninth planet in Solar System

Discovering planet nine can help explain origin and evolution of Solar System, scientists say

Astronomers have narrowed down on the possible location in the Solar System where the elusive planet nine may be hiding, an advance that could shed more light on the evolution of our abode in the Milky Way galaxy.

The hypothetical ninth planet has been a subject of inquiry by scientists for decades due to the unexplained movement of objects at the edge of our Solar System.

Researchers have observed that some objects at the edge of the Solar System – well beyond the orbit of the dwarf planet, Pluto – behave as if they are being pulled around by something yet unseen, which is likely to be another planet.

Discovering this object could help scientists better understand the makeup of the Solar System, its formation as well as evolutionary processes.

Astronomers have been assessing data from Hawaii’s Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) – a collaborative astronomical observation system located at Haleakala Observatory to discover this planet.

Now, researchers have narrowed down possible locations of the hypothetical planet by eliminating approximately nearly 80 per cent of potential locations predicted from previous studies.

“There are too many separate signs that Planet Nine is there. The solar system is very difficult to understand without Planet Nine,” study co-author Mike Brown from Caltech told Universe Today.

“Planet Nine explains many things about orbits of objects in the outer solar system that would be otherwise unexplainable and would each need some sort of separate explanation,” Dr Brown said.

New data, published in a yet-to-be peer-reviewed study, suggests that planet nine, if it exists, is likely to be the fifth largest planet in the Solar System.

Scientists say it could be the only planet in our solar system with a mass between that of the Earth and Uranus.

The largest diameter of the planet’s elliptical orbit around the Sun is expected to be over 500 AU (astronomical units) – about 500 times the distance from Earth to the Sun, or approximately 75 trillion km.

While 78 per cent of the space region predicted to be Planet Nine’s location is ruled out, significant areas remain unobserved to the needed depth, scientists say.

They hope an upcoming survey by the Vera Rubin Observatory could help narrow it down even further.

However, researchers add caution that there’s a possibility of a ninth planet not existing, raising the need for new theories to explain multiple phenomena observed in the outer Solar System.

“Until such explanations are available, we continue to regard Planet Nine as the most likely hypothesis,” scientists added.