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