Is there another hidden world beyond Neptune? Astronomers suspect planet Y

Is There Another Hidden World Beyond Neptune? Astronomers Suspect Planet Y (Image: Canva)

For centuries, people have stared at the night sky, wondering what mysteries might hide beyond familiar planets. Now scientists suggest there could be another unseen world orbiting far past Neptune.

Evidence for a Hidden Planet
Researchers at Princeton University have found unusual patterns. They noticed a warped tilt in the orbits of distant Kuiper Belt objects. The effect could mean a new planet exists.

Amir Siraj, who led the study, explained the case. “If that warp is real, the simplest explanation is an undiscovered inclined planet,” he said. Scientists have tentatively named it “Planet Y”.

This hidden body would be smaller than Earth but larger than Mercury. It could orbit 100 to 200 times farther from the Sun than Earth does.

How Does Planet Y Differ from Planet Nine?
Planet Nine was previously suggested as a possible explanation for distant orbital clustering. It was thought to be ten times Earth’s mass, orbiting far beyond Neptune.

Planet Y, however, explains something different. Its gravity could be tilting Kuiper belt objects about 15 degrees off the solar system’s usual plane. Both planets could exist together.

“Our signal is modest but credible,” Siraj said. The chance of it being coincidence is estimated at two to four percent, similar to early evidence for Planet Nine.

Could Planet Y Really Exist?
Astronomers believe such a planet likely formed closer to the Sun. It may have been scattered outward billions of years ago. Numerical models support this scenario.

Simulations suggest a planet with a mass between Mercury and Earth could maintain the observed tilt. Anything heavier would disrupt nearby regions, making it unlikely.

Jonti Horner, from the University of Southern Queensland, said the possibility highlights our limited knowledge of space beyond Neptune. “We simply don’t know what’s out there,” he noted.

What Comes Next in the Search?
The Vera C. Rubin Observatory will soon begin a decade-long sky survey. This facility could directly detect Planet Y or confirm indirect evidence.

“Rubin will expand the catalogue of trans-Neptunian objects,” Siraj said. If Planet Y exists, we may soon see clearer proof within the survey’s first few years.

For now, Planet Y remains a hypothesis. But astronomy has a history of finding planets through orbital oddities, from Neptune in the 19th century to Pluto in the 20th.

If this new world exists, it could soon move from speculation to reality, reshaping our understanding of the solar system once again.