Did scientists discover a new planet called Planet X or Planet 9? No, that's not true: the research points out the possibility of the existence of a new planet, but nobody has actually seen it or observed it in real life. The observation of the behavior of some other objects in space prompted a group of researchers to hypothesize the existence of a new planet.
The claim appeared in a video (archived here), published on TikTok on May 22, 2023, by the user @Natespiess under the title "Shocking news: there is the 9th planet in the solar system". It opened:
Scientists found 9th planet in the solar system which is called planet X
This is what the post looked like on TikTok at the time of writing:
(Source: TikTok screenshot taken on Mon May 22 10:49:30 2023 UTC)
In January 2015, Caltech astronomers Konstantin Batygin and Mike Brown announced new research that provides evidence of a giant planet tracing an unusual, elongated orbit in the outer solar system. That claim made many people believe that the scientist had found a new planet.
According to the official announcement from Nasa, Planet X has not yet been discovered. The headline of the NASA press release reads, "Hypothetical Planet X". Nobody has seen it yet. It was just a prediction by scientists, and they think Planet X is there because they can see other objects in space being affected by it.
Moreover, Jim Green, director of NASA's Planetary Science Division, said, "This is not, however, the detection or discovery of a new planet. It's too early to say with certainty there's a so-called Planet X. What we're seeing is an early prediction based on modeling from limited observations. It's the start of a process that could lead to an exciting result"
For now, physicists Jakub Scholtz and James Unwin have made the claim that Planet X is, in fact, not a planet at all and could instead be a tiny black hole the size of a bowling ball. Therefore, the claim that scientists have found planet X can not be confirmed.
