Beyond Neptune lies the Kuiper Belt, a vast ring of icy bodies. It is home to Pluto, Makemake, Haumea, and thousands of other objects. This belt should generally align with the orbital planes of the other planets in the solar system. But scientists have discovered something unexpected: the average orbital plane of the distant objects in the belt is tilted by about 15 degrees.
Statistical analysis has shown that this deviation is not accidental. According to Princeton University astronomer Amir Siraj, such a long-term tilt cannot be just a chance left over from the past. Something must be holding it in place. The most likely explanation is that there is an undiscovered planet, larger than Mercury but smaller than Earth.
Scientists suggest that both could exist and together explain various anomalies in the solar system. The soon-to-be-launched Vera Rubin Observatory will conduct the deepest sky survey in history. It will discover thousands of objects in the Kuiper Belt and help determine whether this tilt really exists.
