Since Pluto was downgraded to a dwarf planet in 2006, our Solar System seems to have lost some of its charm. But if some scientists' theories prove correct, we could welcome a mysterious new member of our planetary family: the ninth planet.
Hidden in the depths of space, beyond the orbit of Neptune, this still hypothetical world is making headlines thanks to new research that seems to reinforce its existence. But what do we really know about the ninth planet, and what awaits us in the hunt for this elusive giant of the outer Solar System? If you have two minutes I'll tell you.
Celestial clues: the anomalous orbits of trans-Neptunian objects
The history of the ninth planet begins with a celestial anomaly: the strange orbits of some objects located beyond Neptune, in the most remote region of our Solar System. These bodies, known as trans-Neptunian objects o TNO, have trajectories that seem to be influenced by something invisible and mysterious.
The most striking case is that of Sedna, a dwarf planet discovered in 2004 by Caltech which holds the record for the most distant object ever observed in the Solar System. Sedna has an extremely elliptical orbit inclined to the plane of the Solar System, a behavior that astronomers struggle to explain without invoking the presence of a hidden massive body.
And Sedna is not alone: As scientists have discovered more TNOs, a pattern has emerged that suggests the existence of “something” disrupting their orbits. What could it be? Bammm… The music from those mystery shows, the ones with the chupacabra, fits well here. No, I'm joking. That is, mysteries yes, but always scientific.
The suspect: a 'hidden' ninth planet
Konstantin Batygin e Mike Brown they are the two planetary researchers from Caltech who popularized the ninth planet theory. Their idea, born somewhat as a joke as a reaction to the downgrading of Pluto, is that the orbital anomalies of trans-Neptunian objects can be explained by the gravitational influence of a planet not yet discovered.
This hypothetical ninth planet, or P9 as it is affectionately called, would be a gas giant similar to Neptune, with a mass approximately 5-10 times that of the Earth and an extremely elongated orbit that would take it to distances up to 1000 times that of the Earth and the Sun. A year on P9 would last thousands of Earth years. I had the AI "imagine" it, you can see it in the main image of this article.
So far, no one has managed to directly observe the ninth planet, but this has not discouraged Batygin and Brown. Indeed, in two new studies, one published onAstronomical Journal and the other shared on ArXiv but not yet peer-reviewed (I'll link this too), the two researchers say the evidence for P9 is accumulating.
New research on the ninth planet: an increasingly intriguing cosmic mystery
Analyzing an ever-increasing number of TNOs, as mentioned, Batygin and Brown argue that the best and simplest explanation for their bizarre orbits is that they are caught in the "gravitational perturbations" of a planet we have not yet identified.
How long will we continue with this story, some impatient people will say. Not so much, friends. Researchers are excited about the potential of the future observatory Vera C. Rubin in Chile, which will be turned on in 2025. That will be the moment of truth, given that the Vera C. Rubin will have the sensitivity necessary to find Planet 9 in practically all the expected positions.
This next phase of exploration promises to provide crucial insights into the mysteries of the outermost regions of our Solar System.
Konstantin Batygin e Mike Brown in the arXiv article
What if they find it? A new member in the planetary family
The idea of a hidden world at the edge of our Solar System continues to fascinate scientists, astronomy enthusiasts and supporters of more "heretical" theories. Confirmation of a ninth planet would be an epochal discovery, comparable to that of Neptune in 3.
In addition to rewriting textbooks, this discovery could open new frontiers in space exploration. What could this world so distant and different from everything we know hold? Perhaps exotic life forms, adapted to extreme conditions? Or clues to the origins and evolution of our Solar System?
For now, these are just speculations. But one thing is certain: the hunt for the ninth planet will continue to fascinate us until the grand finale.
