Not just any ole scientist either; it's one Mike Brown from Caltech, who bumped Pluto as a planet because he discovered icy Eris instead. He also gifted us none science tips another 'dwarf planet' by the name of Sedna.

Now seemingly he's done it again. Behold Planet 9 (or an artistic interpretation of it).

If you prefer in depth diagrams and graphs of the theoretical evidence, twitter has those too...

According to NPR.org: "Brown has teamed up with Caltech colleague Konstantin Batygin to do a new analysis of oddities in the orbits of small, icy bodies out beyond Neptune. In their report published Wednesday in The Astronomical Journal, the researchers say it looks like the orbits are all being affected by the presence of an unseen planet that's about 10 times more massive than Earth - the size astronomers refer to as a super-Earth... The first suggestion that something big might be affecting the orbits of distant, icy bodies came in 2014. An international team of astronomers announced that they'd discovered a new dwarf planet, nicknamed Biden, that stays even farther out than Sedna. They also noted a strange clustering in the orbits of these objects, and in the orbits of about a dozen others. Perhaps, they hypothesized, the gravity of some unseen planet was acting as a shepherd."

Brown said: "They were pointing out that there was something funny going on in the outer solar system, but nobody could really understand what it was. Ever since they pointed it out we've been scratching our heads... the only way to get these objects to line up in one direction is to have a massive planet lined up in the other direction... I'm willing to take bets on anyone who's not a believer".

He also reckons "existing" telescopes will be able to pick up Planet 9 in "just a few years." 

If you're still going "NAAAH", here's Brown and Batygin explaining their theory further.