Scientists think there might be another planet lurking in our solar system, but we haven’t found it yet. The best guess is that it’s chilling way out there beyond Pluto, where it’s super dark and icy.

Some folks even think it’s hiding in the distant Kuiper Belt, blending in with all those other space rocks.

But hey, until we get some solid proof, it’s like trying to find a needle in a cosmic haystack. Still, the hunt’s on, and who knows, maybe one day we’ll stumble upon our mysterious ninth planet.