Scientists offer new evidence of 9th planet in Solar System

It might be hiding beyond Neptune.

The existence of a ninth planet in the Solar System – after Pluto’s declassification as a planet in 2006 – has been speculated for a long time and researchers at the California Institute of Technology (CalTech) claim now that they hold new evidence to support this theoretical guess.

In two recent studies - one published in the Astronomical Journal and the other yet to undergo peer review - proponents of the idea of a hypothetical "Planet 9" argue that this elusive world might have been within our grasp all along. 

In short, it could be hiding somewhere beyond Neptune, the farthest known planet in the Solar System.

The core of the theory, championed by planetary researchers Konstantin Batygin and Mike Brown from CalTech, hinges on the behavior of trans-Neptunian objects (TNOs), which float beyond Neptune’s orbit in the outer reaches of our celestial neighborhood.

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These TNOs, particularly Sedna — a dwarf planet discovered by CalTech scientists in 2004 and considered the most distant object ever spotted in our Solar System — exhibit peculiar orbits deviating significantly from the norm.

As scientists learned more about these enigmatic objects, a discernible pattern emerged, suggesting an external gravitational force at play.

Dubbed as "Planet 9" or P9 among some planetary scientists following Pluto's demotion in 2006, this theoretical celestial body emerged as a speculative solution to the TNOs' orbital anomalies. What if, as Batygin and Brown pondered, an unseen planet exerted influence on their trajectories?

While direct observation of such a planet remains elusive, the latest papers by Batygin and Brown assert that, based on extensive analysis of TNOs, the most plausible explanation for their peculiar orbits is the gravitational influence of an as-yet-undiscovered planet.

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The next course of action, they emphasize, involves harnessing the capabilities of upcoming space observatories to hunt for P9, recognizing that its detection may still be some time away.

There is hope that the commissioning of a new – the world’s most powerful – telescope for the Vera C Rubin Observatory in Chile, scheduled for 2025, will enable astronomers to detect the enigmatic P9.


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