Last year, two astronomers from Caltech shocked the science community when they announced that they had ironclad evidence pointing to a planet orbit at the farthest edge of our Solar System. They dubbed the mysterious lurker Planet 9, or Planet X, claiming the object was roughly 10 to 12 times the mass of Earth and orbiting so far out that it takes up to 20,000 Earth years for the planet to complete one loop around the Sun.
We haven’t exactly seen this planet yet
The only problem with the astronomers’ discovery? We haven’t exactly seen this planet yet. The two astronomers — Mike Brown and Konstantin Batygin — inferred the planet’s existence based on the strange movements of six small objects in the Kuiper Belt. That’s the large cloud of icy bodies that orbit beyond Neptune. Since then, even more evidence for Planet 9’s existence has been stacking up, further solidifying that the object is out there. Still, seeing the object will be the biggest confirmation of all. The astronomers are working on it, but it may be some time before we spot it.