The BBC Future article "If Planet Nine Exists, Why Has No One Seen It," published on February 16, 2021, unfortunately presents a very biased view of the ongoing planet debate. Instead of acknowledging the continuing debate over Pluto's planet status and how to define the term "planet," the article presents only the position of the International Astronomical Union as if it were a done deal, which it is not.Just four percent of the IAU voted on the controversial 2006 demotion of Pluto, and their decision was immediately rejected in a formal petition by an equal number of professional planetary scientists. Yet nowhere is this mentioned in the article. Instead, the writer simply makes the biased statement, "the ninth planet was no more" regarding the aftermath of the IAU 2006 vote, completely ignoring the fact that the majority of planetary scientists reject that decision to this day.
In this Science Direct paper, planetary scientist Phil Metzger discusses the history of planetary classification and the fact that planetary scientists do not use the IAU definition in their peer-reviewed published papers.
Those who reject Pluto's planet status completely ignore the stunning revelations of active geology and planetary processes on Pluto by the New Horizons probe in 2015.
Nowhere does the article mention the alternative geophysical planet definition, presented by planetary scientist Kirby Runyon at the Lunar and Planetary Sciences conference in 2017 and in a 2018 article in Astronomy magazine. This definition views dwarf planets as a subclass of planets and therefore keeps Pluto, Ceres, Haumea, Makemake, and Eris in the planet list. It is the definition preferred and used by most planetary scientists.
Also problematic is the repeated quoting of Mike Brown, a controversial figure who represents just one side in this debate. Brown unprofessionally promotes himself as the man who "killed" Pluto, and it is disappointing to see the writer repeat this without question and even promote his twitter account. Brown was one of a team of three who discovered Eris, but he did not "kill" planet Pluto, and journalists should not be promoting this nonsense. Notably, the other two members of the discovery team reject the IAU planet definition in favor of the geophysical one.
Brown controversially named the hypothetical planet in question "Planet Nine" to further promote the self-serving notion that he "killed" planet Pluto. In 2018, a group of planetary scientists formally objected to this term in their publication Planetary Science Exploration Newsletter because of its inherent bias. There, they noted that the appropriate professional term for a hypothesized but undiscovered planet is "Planet X," with "X" referring to the unknown, not the number 10.
It is unfortunate that some scientists continue to mislead the public by promulgating their own biased positions as fact, without even acknowledging the existence of a debate or of other legitimate scientific positions. I urge the BBC to be more vigilant in the future when it comes to the planet definition debate to use neutral language that acknowledges the fact that this issue is not settled but remains an ongoing debate in the science community.