>>40737441It's not a planet. It's an object about the tenth the size of our moon. It's also not the only object of it's kind. These objects are called Sednoids, following a trajectory far beyond the orbit of Neptune. Further, it wasn't just discovered. There's pictures of it dating back 19 years - the discovery here is that it can be classified as a Sednoid - that is to say, NASA now was able to confirm that it follows a stable orbit in the outter solar system.
>>40737489Again, not a planet and this discovery most likely disproves the planet 9 theory, because Ammonites orbit would likely not be possible if said planet 9 actually existed.