New discovery reinforces arguments for Elusive Planet 9

Years after its detection proposal, Planet 9 remains stubbornly absent from our astronomical maps. Proof of its existence is found only indirectly in the orbits of several trans-Neptunian objects, or NWT, which follow paths around the sun that collectively imply the presence of another larger planet in the far reaches of the Sun. solar system.

The biggest problem with Planet 9 is that we did not find it. The biggest problem for those who want to argue that it does not exist is that we continue to find it. The most recent piece – rock? – The proof is 2015 TG387, colloquially known as "The Goblin". What makes the goblin so interesting is what he is not do: namely, interact with other planets in the solar system. He is never close enough to Jupiter, Saturn, Uranus or Neptune to be gravitationally influenced by them. However, its orbit around the solar system shows that it is clearly influenced by Something.

All "giant planets" are located on the far right of the image. This is the distance that separates us from 2015 TG387.

"It never interacts with anything we know in the solar system," says Scott Sheppard, astronomer at the Carnegie Institution for Science and co-discoverer of the 2015 TG387. "In one way or another, he had to find himself in that elongated orbit in the past, and that's the big question: with what did he interacted to get [there]? "

The mathematical simulations show only one real possibility – 2015 TG387 has been moved into a very elongated orbit by interactions with a larger body, which corresponds to the assumed characteristics of our hypothetical Planet 9. One of the problems to find the actual planet is that far from the sun are extremely weak. The goblin spends most of its time too far from the Earth to be detected by telescopes and can only be seen when it is at its closest approach to the Sun, which only happens every day. 40,000 years. In other words, the only reason we found it is that it is in the right place in its orbit (about 300 km in diameter, Goblin is much smaller than Ceres).

There are critics of the planet 9 theory, including those who believe that the collective gravity of these small objects may have pushed them into strange elliptical orbits, or that the problem as a whole is an artifact sampling based on an examination of a small part of the sky. If we see these unusual elliptical orbits throughout the solar system, it would mean that they are caused by something else (no one expects the space to be filled with invisible planets whistling).

It's early in every case. Planet 9 could simply be too far from the Earth to be observed at the moment, thanks to a combination of dark surface albedo, distance and us not knowing where to look. Previous surveys have clarified many objects are not over there; For example, we do not think that a planet the size of Jupiter can still hide elsewhere. But there are still gaps in our knowledge that could hide a distant ice ball.

Now read: We may not need "planet 9" to explain the unusual orbits of the outer solar system, almost two years later we still do not know if the new planet exists, and the theoretical planet 9 could be a rogue planet that is not native to our solar system