A few years the scientific world talks about the possibility of the existence of the ninth planet in the solar system (Pluto, I'm sorry). Perhaps this object is located on the outer edge of the solar system, much further than the planets of the outer circle. So far, there is no direct evidence, but indirect evidence is gradually accumulating.
For the first time, scientists have announced the possibility of the presence of a huge object in the solar system in 2016. At that time, US astronomers Mike Brown and Konstantin Batygin monitored asteroids and comets in the outer regions of the solar system for a long time. It turned out that these objects behave somewhat strangely.
After that, another group of scientists, an international team, used the data obtained during the implementation of the Dark Energy Survey experiment. Then
a new BP519 trans-Neptunian object was
discovered (this is not the planet in question in the article). According to experts, its orbit is very elongated. The small radius of the orbit reaches 35 astronomical units, while the large - 862 astronomical units. The difference is more than 20 times! In addition, the orbit of this object is very strongly inclined relative to the orbital plane of the planets of our system - approximately 54 degrees.
Perhaps astronomers say that this object was captured by our system in the distant past. If this were not so, and BP519 would form together with all the other elements of our system, then the plane of its orbit would be the same as that of other planets and planetoids. And this is not the case, which speaks in favor of a possible capture.
By the way, 2015 BP519 can be quite large and represent not an asteroid, but a planetoid like Pluto.
For several years, astronomers have carried out computer simulations of the parameters of a planetoid orbit, trying to explain its appearance by formation during the evolution of the system. But calculations have shown that the characteristics of its orbit, including the inclination, could not be affected by any of the known planets in the solar system. Thus, another factor appears, and this is probably the ninth planet.
In order for the influence to be so powerful, it is necessary that the ninth planet be large. In this case, its mass is four or more times the mass of the Earth. A year on a planet that is still undetected is equivalent to 10–20 thousand years on Earth.
If she really exists, then her search will become a non-trivial task. It may be outside the solar system, although it is still under the influence of the sun. This means that it is simply impossible to detect it with telescopes. And in order to find it, you need to know exactly where to look. Without this, detection can occur only by chance.
Most likely, evidence of the presence or absence of the ninth planet will be obtained through indirect data. For example, astronomers will find a few more transuranic objects, calculate their trajectory and find out if something is affecting them or not.