Planet 9 is probably not as far away as we thought

 There is said to be another undiscovered planet in our solar system. A research team assumes that Planet 9 is closer to us than experts think.

In our solar system there are eight planets, a few dwarf planets and a lot of other celestial bodies. One or the other object could still be undiscovered. In fact, experts have been thinking for some time about an unknown and Earth-like Planet Nine (P9) , which is said to be located behind the orbit of Neptune and behind the Kuiper Belt.

Because beyond Neptune there is a strange grouping behavior of some trans-Neptunian objects (TNOs). To date, 3,300 of these objects with a diameter of more than 100 kilometers are known.

However, astronomical experts estimate that there are approximately 70,000 objects located in the Kuiper Belt at a distance of 30 to 50 astronomical units (AU; one AU corresponds to the distance between the Earth and the Sun).

The formation of groups and the sometimes strange orbits of some TNOs are said to be an indication of an undiscovered planet whose gravitational forces affect other celestial bodies. Planet Nine is said to be at a distance of 400 to 1,500 AU, with the most likely accurate models assuming 700 AU.

Planet Nine is probably not a giant

The research duo now found a slightly different explanation for the behavior: According to this, it is not an object with a strong gravitational pull, but rather a more modest, Earth-like world, which is said to be much closer to us than the controversial Planet Nine - namely maximum 250 to 500 AU away from the sun.

By the way, Neptune is about 30 AU (4,495 million km) from the Sun. Other studies have also assumed that P9 cannot be found quite so far out.

"We found that an Earth-like planet in a far off and slanted circle can make sense of three major properties of the far off Kuiper Belt: an unmistakable populace of TNOs with circles past the gravitational impact of Neptune, a huge populace of high-slant objects and the presence of a few outrageous items with exceptional circles ," says the ongoing review.

Possible explanation for "strange" behavior of other objects

According to the researchers, the object is said to have an inclination of 30 degrees relative to the plane of the solar system, which could explain the strange behaviors of other celestial bodies - which ultimately indicate the presence of something larger. The presence of P9 could, in turn, explain objects with an inclination greater than 45 degrees and the orbits of the dwarf planet Sedna, for example, which has a strange and unusually elongated orbit.

The research team assumes that the world is frozen and dark due to its great distance from the sun. It is said to have a mass 1.5 to three times that of Earth.

The most distant single object known to date in our solar system was 132 AU from the Sun. Pluto is located at an average distance of about 40 AU from the Sun.

Further investigations are necessary

However, beyond Neptune there are a whole bunch of other icy rocks and dwarf planets. In recent years, space telescopes and survey projects have discovered several new trans-Neptunian objects.

One such pattern is clustering, which found some groups of TNOs clustering and moving together in groups on inclined or tilted orbits.

More research is needed, and there will be many more theories surrounding Planet Nine. Maybe even more crazy ones like the one that says the planet is made of dark matter . In order to find P9 or rule it out, knowledge of the orbital structures in the distant Kuiper Belt must be better understood.