Two studies published on arXiv have identified the hypothetical ~10 Earth mass "Planet Nine" as an explanation for the tilt of the solar system:
Two recent studies have shown that the existence of a mysterious, hypothetical Planet Nine could explain why the planets in our Solar System don't fully line up with the Sun. Researchers have been speculating about a ninth planet since January this year, and these latest studies add more weight to the hypothesis that, at some point in time at least, there was an extra planet orbiting our Sun. In fact, if Planet Nine does exist (or did), it would help to explain something that scientists have puzzled over for decades - why the Solar System is tilted.
What does that mean? Well, basically, all of the main eight planets that orbit our Sun do so on the same plane, making the Solar System look like a disc. The problem is that the Sun spins at a different angle, with its axis roughly 6 degrees off from the rest of the planets.
In the past, researchers have attempted to explain this slant by blaming the temporary tug of a passing star, or interactions between the Sun's magnetic field and the disc of dust that formed our planets. But none of these hypotheses have fully accounted for the misalignment. But now the two new studies – [completely independent] from one another in the US and France – show that the existence of Planet Nine could explain the tilt.
Solar Obliquity Induced by Planet Nine
(Score: 2) by tangomargarine on Tuesday July 26 2016, @09:20PM
Yes, I know what you're saying. I don't see how whether you call it a "planet" or "dwarf planet" has a significant impact on *anyone*, including scientists.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"