The idea of a preivously unobserved planet in our solar system beyond Pluto has existed for some time. These ideas are usually the product of conspiracy theorist, fantasy or science fiction. However, two astronomers from Caltech in Florida are now saying these theories may in fact be true! They have conducted computer simulations and other mathematical models to describe the strange movement of objects in the Kuiper Belt. The result is the potential for a planet the size of Uranis or Neptune beyond the orbit of Pluto. Such a planet would orbit the Sun every 10,000 to 20,000 years, while Pluto orbits the Sun every 248 years.
So far, the planet exists only in theory. No one has observed Planet X (or Planet 9), which is why Mike Brown, one of the astronomers behind the discovery, is urging scientist to search for in. "If Planet X is out there, we'll find it together. Or we'll determine an alternate explanation for the data weve received so far. Now let's go explore!" - Mike Brown.