There is a lot of speculation that there may be a ninth planet out there in the distant reaches of our solar system, but for the life of them, astronomers have been unable to find it.
Evidence that some kind of massive entity exists out there because the outermost known planets in our solar system have a strange orbital pattern that appears to suggest something massive, besides our Sun, is torquing on them with gravitational forces.
If Planet Nine, as it has subtly been named, actually exists, scientists expect it to be a gassy planet about 10 times the size of Earth.
But then again, scientists still want to know how it got here. So they turned to computer models to predict more possibilities of its origin.
As far away as scientists believe Planet Nine may be, there simply isn't enough material out there to form a planet. Most useful material was already used to form the planets that exist already, and in places where the material didn't have the gravitational forces necessary to make planets, we have the Asteroid Belt and the Kuiper Belt.There's also a massive gap in between where planets exist in our solar system and the possible location of Planet Nine.
The latest theory is that Planet Nine may have been “kidnapped” from its original host star around 4.5 billion years ago. The theory is revealed by astronomers in the Monthly Notices of the Royal Astronomical Society.
Planet Nine would exist very far out in our solar system. Because of this, there is evidence to suggest the theory that the planet could be an exoplanet that was taken from its own host star by our Sun’s gravitational pull while our solar system drifted closely to another system in the distant past.
The “fly-by,” as you could call it, may have stolen Planet Nine out of its original orbital course and ripped it right into our own solar system.
Of course, our solar system is nowhere near any other host stars at this point in time, but the universe is constantly expanding, which would mean that at some point in the past, our solar system would have gotten close to another system in our galaxy to swipe an additional planet and is now too far away from any other systems.
This theory is a leap of faith, but it would mean that Planet Nine is actually an exoplanet and, if true, it would make Planet Nine the first known exoplanet to exist in our solar system.
"It is almost ironic that while astronomers often find exoplanets hundreds of light years away in other solar systems, there's probably one hiding in our own backyard," said Alexander Mustill, an astronomer from Lund University.
The problem with this theory is that we don’t even know if Planet Nine actually even exists. There are circumstances out there that suggest there may be something out there, but there is no concrete evidence yet. Since there is no confirmed existence of such a planet in our solar system just yet, it’s hard to make prediction theories this early in time.
Source: Lund University