10th Planet Discovered

There have been other 10th planets (both real and imagined) before, but none were big enough to be considered as planets. But this one...

Its sheer size in relation to the nine known planets means that it can only be classified as a planet itself, Brown says.

Now maybe the debate on whether Pluto is a planet can end since invalidating Pluto would invalidate this one, too. NASA will also have to update this page: Is there a Planet X or 10th planet?