Planet 9: everything you need to know about the candidate for the ninth member of the solar system

At school we were taught that there are eight planets in the solar system. Depending on the distance from the Sun, from closest to farthest, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. This does not include Pluto, which is considered a minor and dwarf planet. Contrary to this concept, two researchers from the California Institute of Technology (Caltech) revolutionized astronomical knowledge by postulating the possible existence of Planet 9. Yes, it would be the ninth member of a system dominated by its great star and around which, according to consensus, an octet of giants orbits.

speculations about the ninth planet They’re not exactly new. Already in 2016, astronomers Konstantin Batygin and Michael Brown from the California Institute of Technology conducted mathematical studies to conclude its presence beyond Neptune, in the galactic redoubts farthest from the Sun. reveals the “most compelling evidence” of its existence. Of course: this is still a hypothesis, since it has not yet been seen in telescopes.

IN paper In a paper published in April, Batygin and Brown push for the idea of ​​a new trans-Neptunian planet, which they call Planet 9. Some data before turning to the origins of the proposal and recent discoveries. This cosmic body is also known as Planet X, P9 and Fatty. will be 10 times the mass of the Earth, similar in size to Uranus. Except, It would be 20 times farther from the Sun than Neptune.. This is a significant distance: according to calculations, it is about 30 billion kilometers from our planet.

Planet 9: origins of speculation

To touch the great cosmic mysteries, you don’t have to look at exoplanets, those located outside the solar system. There is intrigue in this too area Universe. Planet Nine is without a doubt one of those unknowns. As we noted, Batygin and Brown initially hypothesized its existence back in 2016 in a study published in the journal Astronomical magazine. They previously announced an investigation in January 2015.

On this occasion, NASA noted in a statement that researchers at the California Institute of Technology discovered mathematical evidence indicating the presence of Planet 9 in the depths of the solar system. Like other similar objects, it will revolve around the Sun. In their first approaches to this cosmic mystery, they estimated that it would take 10,000 to 20,000 Earth years to complete a full, “extended and unusual” orbit.

The US space agency clarified in almost all caps that the study published by Caltech astronomers “does not mean that a ninth planet exists,” that “the existence of this distant world is only a hypothesis,” and that it was not conducted. there is no direct observation of the object. Bye, What did Brown and Batygin rely on to bring Planet X before our eyes? Essentially, mathematical predictions that could explain the singular motions in the orbits of certain objects. Trans-Neptunians. Indirect clues, but clues nonetheless.

Why do Caltech researchers “believe” in a ninth member of the solar system?

As we indicated earlier, So far, we have no visualizations confirming the intriguing Planet 9.. Instead, there are mathematical proofs and computer simulations. “This is the beginning of a process that could lead to exciting results,” Jim Green, then director of NASA’s Planetary Science Division, commented several years ago.

The focus of this study, the ratification of which would revolutionize our concept of the solar system, is Kuiper Belt, a ring of icy bodies located beyond the orbit of Neptune. Astronomers studying the region have noticed that some dwarf planets and other elements tend to orbit in clusters. By analyzing these pathways, the University of California team predicted the possibility of a large body that also meets the necessary conditions to become a planet. In their research, they calculated that Planet 9’s gravity could explain the unusual orbits of the aforementioned Kuiper objects.

“The strongest evidence” supporting the existence of Planet 9

More than eight years after the evidence was first revealed, Brown and Batygin return to the ring with a thrilling announcement. They claim that they have come to more convincing evidence about the existence of the planet. In a new study – you can read it in full here in English – they say they have tracked the movements of objects crossing Neptune’s orbit, which represent bumps in their trajectory.

Such dynamic instability in trans-Neptunian objects has two possible explanations. First: the impulse is due to the interaction of Neptune’s orbit and the galactic tide. The second thing that calls us here: the movements are caused by Fatty. After running simulations in each case, the Planet Nine hypothesis showed a confidence level of 5 on a scale of 6. In this spirit, Batygin indicated that they now have convincing data confirming the existence of a new gas giant. “Planet 9 really exists,” he noted.

The next step will be the great eureka in this investigation. At this time, there are various telescopes searching for the celestial body. The greatest enthusiasm is generated by a completely new LSST, a super-powerful device that was recently installed at the Vera Rubin Observatory in Chile.. As explained Wired, this instrument is designed to reveal the secrets of the Universe. It has everything you need: it will take up to 1,200 images of the same area of ​​the sky, “allowing us to explore space in unprecedented depth compared to other ground-based telescopes.”

“I would really like to find Planet Nine,” said Michael Brown. “In any case, I would also be very happy if someone else found it. We hope others will be inspired and start searching,” he concluded.

And one last detail. “Planet 9” was the name chosen by Caltech researchers and mentioned in their research. However, “the actual naming rights to an object belong to the person who actually discovered it,” NASA explains. In this sense, if this world is found, the final name must be approved by the International Astronomical Union (IAU). In this case, will they continue the tradition of worshiping the gods from Roman mythology, borrowed from Greek culture?

Why is Pluto not considered the ninth planet?

In the past there were another member of the solar system, occupying the ninth “chair”: Pluto. It was discovered in 1930 by American astronomer Clyde Tombaugh. Having a small, marble-colored body, it lost its planetary classification in 2006. One of the people responsible was the researcher we met here, Michael Brown of the California Institute of Technology, who published a book that same year called How I killed Pluto and why he deserved it.

In dialogue with National GeographyBrown quips: “People think that if you call it a planet, it must be a planet. I say, are seahorses horses?” The astronomer’s consideration was as follows: Pluto does not meet the conditions for us to consider it a planet. Correctly said. What are these criteria? According to the IAU, it should orbit the star and be large enough to take on a circular shape due to its own gravity. Additionally—and this is key to Pluto’s classification—it must be gravitationally dominant in its orbit in order to purify other bodies.

According to NASA, Pluto is a dwarf planet. Just under a decade ago, it was classified among three other solar system objects that are roughly the same size as Pluto: Ceres, Makemake and Eris, which are much smaller than the eight known planets.

Brown concluded: “At this point, the existence of Planet 9 is a very good proposal to explain many of the things we see there for which we have no other explanation. But until the day we look at it and say, “Aha, this is it,” this will be the best hypothesis to explain these phenomena. I think one day we’ll point a telescope and see it, but until then it’s a hypothesis.”