A huge and mysterious Tenth planet.

The ninth planet ( Planet Nine) is a planet predicted to be about 10 times the mass of our Earth, orbiting somewhere in the distant Solar System . This was predicted back in 2014, and since then we have been finding more and more evidence of its existence in our Solar System.
The main evidence for the existence of the ninth planet lies in the strange patterns observed in Kuiper Belt objects outside of Neptune . A cluster of these objects was observed with orbits of the same shape that all move in the same direction, rather than the random orbits that we expect from them. The orbits are also deflected by some larger source of gravity. While there is a 1 in 14,000 chance that this could be a coincidence, scientists agree that with the increasing amount of evidence, it is extremely unlikely that it is all random. The most convincing conclusion, of course, is the existence of this elusive planet number nine. The Kuiper belt itself cannot be the cause of these anomalies, as it must be 100 times larger to have such an impact on this cluster of objects.
The assumption is that the Ninth Planet and the Kuiper Belt objects are in resonance with each other, similar to the orbital resonance shared by Pluto and Neptune. This means that their orbits intersect with each other and are synchronized, but the planets and objects themselves never collide.
How the gravity of the theoretical ninth planet affects the orbits of a cluster of Kuiper Belt objects.
We also know that the Sun’s axis is tilted about six degrees to the plane of the ecliptic. The presence of the Ninth Planet may mean that the plane of the ecliptic is actually tilted.
The collision of planets early in the formation of our Solar System could have caused the orbit of the Ninth Planet to deviate from the orbits of other planets, causing our entire Solar System to tilt to compensate for this difference. Computer simulations give the orbital inclination of the Ninth Planet to the plane of the ecliptic at 30 degrees — a number that perfectly matches current observations of the orbits of the known planets of the Solar System.
The distance of the Ninth planet from the Sun is estimated at 300-900 times greater than the similar distance of the Earth, and the orbit of this planet is so large that one year (the period of rotation around the Sun) on it will be equal to 10-20 thousand earth years.
It sounds too incredible to believe, but keep in mind that our knowledge of the universe is still incomplete. Our old geocentric model of the Solar System, which put the Earth at the center, was adopted for more than 1,000 years before being replaced by the heliocentric model in the 17th century. And yet the geocentric model was still accurate in predicting the celestial cycles, the seasons, everything we needed at that moment for life and agriculture.
The existence of Neptune was known long before it was recorded in the firmament. Anomalies in the orbit of Uranus have led to the assumption that some other body is interfering and changing the trajectory of this planet. Many astronomers in the 1800s noticed this, so by the time Neptune was discovered in 1846, it was impossible to decide who really made the discovery first. Similarly, anomalies in the orbits of Neptune and Uranus led to the discovery of the dwarf planet Pluto in 1930. The calculations of Neptune’s orbit were so accurate that it was found less than one angular degree from where it should theoretically be, according to the calculations.
So, if there is this huge planet in our Solar System, why is it taking us so long to discover it? Well, first of all, we don’t know exactly where to look. Unlike Neptune, we have no coordinates for where this new planet might be located in the vast expanse of a distant solar system. Secondly, because it is very far from the Sun, and probably the reflected light from this planet is not visible. It is also important at what point in its orbit it is now-the closest to the Sun or at its farthest point?
Until we directly detect it, there is a testable hypothesis that says that if the planet is there, then objects on the opposite side of the Solar System should have orbits similar to those of the Kuiper Belt cluster of minor planets.
“Every time I did calculations and got a known structure of the Solar System, I also saw these objects with orbits outside of Neptune. I think it is becoming increasingly inconvenient to have a Solar system without a Ninth Planet. “
Konstantin Batygin, astronomer, one of the discoverers of the ninth planet of the Solar System.
Other theories claim that the Ninth Planet was actually captured from the outside by the gravity of our Solar System, and not formed with it.
At the moment, we only have about a dozen parameters that give us clues about the existence of the mysterious Ninth Planet. Nevertheless, this is quite convincing evidence of the existence of a new unknown world in our Solar System, which gives us a more complete picture of it and the history of its origin. But the question remains: “Are there still other worlds in our star system waiting to be discovered?”