An undiscovered planet could be hiding well beyond the orbit of Neptune. However, some astronomers now believe it may take 1,000 years to find that distant world.
The solar system is divided into several regions. The area closest to the Sun consists of small, rocky, terrestrial planets – Mercury, Venus, Earth, and Mars. Further these worlds lie the gas giants – Jupiter, Saturn, Uranus, and Neptune. Beyond this region are the small, icy bodies, including Pluto, orbiting in the distant Kuiper Belt. Orbits of these small bodies suggest there may be a far-flung planet orbiting in the depths of the solar system.
“The possibility of a new planet is certainly an exciting one for me as a planetary scientist and for all of us. This is not, however, the detection or discovery of a new planet. It’s too early to say with certainty there’s a so-called Planet X. What we’re seeing is an early prediction based on modeling from limited observations. It’s the start of a process that could lead to an exciting result,” said Jim Green, director of NASA’s Planetary Science Division.
If such a world exists, the body would likely lie between two and 15 times as far away from the Sun as Pluto, taking 10-20,000 years to orbit once around our parent star. Such a planet would likely be 10 times more massive than Earth, but finding it would remain elusive due to the great distance and lack of light that far from the Sun.
It is possible that Planet Nine may have begun its life as a gas giant, like Jupiter or Saturn, but was thrown to the depths of the solar system by the tremendous gravitational forces that exist near those massive worlds.
Although some astronomers speculate that a planet nine could exist, others believe the orbits they observe in distant objects of the solar system could be the result of thousands of tiny objects in the Kuiper Belt.
If planet nine does exist, there is a possibility that gravity from that world would be able to nudge frozen asteroids toward the Sun. Some of these objects may even, occasionally, impact our home world.