The search for the mysterious Planet Nine continues, and recent research claims to have found the “strongest statistical evidence yet” for a planet orbiting the outer reaches of our Solar System. This assertion comes from Konstantin Bogytin, an astronomer at the California Institute of Technology (Caltech), who has previously contributed to studies seeking to prove the existence of this elusive planet.
In this latest study, Bogytin and his team tracked the movements of Trans-Neptunian Objects (TNOs), celestial bodies that exist beyond the orbit of Neptune. This category includes various bodies of different sizes, such as dwarf planets like Pluto and Eris.
The team specifically focused on a group of TNOs known for their unstable movements due to Neptune’s gravitational influence. This instability makes their paths challenging to interpret, but the researchers sought to use them to gather insights about Planet Nine’s possible existence.
Using computer simulations, the researchers combined the known forces of the planets, passing stars, and the galactic tide from the Milky Way to analyze these erratic TNOs. They ran two sets of simulations: one assuming Planet Nine’s presence, and another assuming it doesn’t exist.
“Accounting for observational biases, our results reveal that the orbital architecture of this group of objects aligns closely with the predictions of the P9-inclusive model,” the researchers write in their paper. The findings suggest that the data is consistent with a scenario where Planet Nine exists, whereas its absence would make these rogue TNOs’ behavior highly unlikely.
However, Bogytin and his colleagues admit they’re far from conclusive proof of the planet’s existence. Attempts to detect Planet Nine by observing its potential impact on other Solar System bodies have so far failed to provide solid evidence.
With new, more powerful telescopes like the Vera C. Rubin Observatory in Chile, astronomers hope to shed light on this mystery. The researchers believe these advances could bring more clarity to the Planet Nine debate and enable rigorous testing of their assumptions.
Considering the estimated size and distance of Planet Nine—a mass roughly five times that of Earth and a distance 500 times farther than Earth’s distance from the Sun—spotting it directly remains challenging. Pluto, by comparison, is only about 40 times farther than Earth, illustrating the difficulty in detecting such a distant object.
“As importantly as the comparison with existing observations, the results presented herein offer a set of readily-falsifiable predictions, with near-term prospects for resolution,” the researchers conclude.
The study has been accepted for publication in the Astrophysical Journal Letters and is available on the preprint server arXiv for review.
