We have been looking for Planet 9 of the Solar System for years. And we’re running out of places to look

The further we get from the Sun, the more difficult it is to observe objects since most do not shine with their own light but rather reflect that of our star. It is therefore not surprising that many astronomers consider very seriously the possibility that a planet is hiding in the confines of our solar system. Many are looking for it, but are running out of places to look.

The origin of the ninth planet.
Humanity has been observing the stars for millennia, and from that observation we have been discovering all the planets of our solar system one by one. About. The discovery of Neptune was all the more unique as it was not discovered through direct observation, but by the effect of its gravity on the motion of other planets. Astronomers knew where they had to point their telescopes to see the eighth planet.

To explain some more orbital oddities, experts from the California Institute of Technology (CalTech), proposed the existence of a “Planet 9”, a planet similar in size to Neptune but that would orbit the Sun at a much further distance, beyond even that of Pluto. Also know as “Planet X”, this planet candidate would be difficult to detect because of its position so far from the Sun, much more than Neptune was in its day.

Between 700 and 8000 AU.
A couple of British researchers began to review data from two surveys of our sky in search of this supposed hidden planet. The analysis carried out will be published as a Article in the magazine Monthly Notices of the Royal Astronomical Societybut your draft is available via repository ArXiv. In it, the researchers give an account of their search.

Based on the expectation that the planet, due to its remoteness, would orbit at a slow speed, they took surveys separated by almost 23 and a half years. This should be enough to be able to detect the movement of Planet 9 on its path around the Sun. They limited their search in space to a disk located around the plane in which most of the objects in our system orbit and at a distance between 700 and 8000 astronomical units (AU) from the Sun.

The analysis allowed them to detect a total of 535 objects that could correspond to this planet. These objects were at less than 1000 AU away and they had masses less than that of Neptune, which made them a priori good candidates for Planet.

Discard game.
The next step for the researchers was to analyze each of the individual features of these objects in the infrared spectrum. The result was that none of these “infrared signatures” corresponded to the one that could leave a planet. That is, back to square one.

The reason is that these objects were in the vicinity of “cirrus clouds”, possible real causes of the signals captured by the team of researchers.

A vanishing planet.
Although the absence of evidence is not in itself evidence of an absence, this study reduces our chances of finding this ninth planet. Even more so if we take into account that it is the second study of these characteristics that ends empty-handed.

Earlier this year, a survey conducted by the Atacama Cosmological Telescope (ACT) in Chile did not find a trace of the elusive and theoretical planet. Those responsible for the study explained, yes, that the tools they had were not enough to fully rule out the planet, but in any case they did not find it either.

The recent study covered a good deal of ground in which a sizable planet capable of influencing the orbits of other objects in our system might hide. If it is not there, it is more difficult to speculate on what its location could be, perhaps in a very eccentric orbit or perhaps outside the plane of our system.

The search continues.
Sometimes the investigations that arrive empty-handed are as relevant as those that are not. Science must refine and even discard theories in order to advance, which affects all fields.

Planet 9 gives us an almost science fiction scenario, but it should not be forgotten that it is a theory that tries to answer an enigma: an anomaly in the paths of the planets in our solar system. Whether it exists or not, the answer to this question will undoubtedly open up new avenues of exploration for us to understand what is around us.

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