Pluto was stripped of planet status in 2006, but at the conclusion of a recent high-profile debate, an audience voted overwhelmingly to sort of reinstate Pluto as a full-fledged planet, inflaming passions once again over the controversial designation.
According to The Washington Post, the International Astronomical Union (IAU) – "arbiter of what is and what isn’t a planet" – downgraded Pluto after drawing up three criteria for planethood that Pluto didn't meet.
Those requirements said all true planets should "be in orbit around the Sun, be round or nearly round, and be shown to have 'cleared the neighborhood' around its orbit" that is, be gravitationally dominant. In the face of these new requirements, Pluto was downgraded to a "dwarf planet," and the science community was thrown into chaos.
One organization that took issue with Pluto being shunted into the gray area between the lowly status of the rocks in the asteroid belt and full-planet citizenship was the Harvard-Smithsonian Center for Astrophysics.
Seeking to re-evaluate Pluto's planet-ness,
it called for a grand debate between experts in the field on Sept. 18.
Science historian Dr. Owen Gingerich, who chaired the IAU planet definition committee, presented a historical argument in favor of restoring Pluto to its office.
"A planet is a culturally defined word that changes over time," went the crux of his argument.
Dr. Gareth Williams, associate director of the Minor Planet Center, presented the IAU's segregationist viewpoint, arguing that a multitude of sun-orbiting, roundish rocks roughly the size of Pluto have been found in recent years. If all of those were included as planets, the number of planets explode to 25 immediately, "with the possibility of 50 or 100 within the next decade" as we continue to explore the solar system.
"Do we want schoolchildren to have to remember so many? No, we want to keep the numbers low," he said,
according to Time magazine.
The third and final debater, astronomer Dimitar Sasselov, director of Harvard’s Planets and Life initiative, argued that we don't yet know enough about the variety of celestial bodies strewn across our solar system and the larger galaxy, so we should shy away from definitions for now, and call Pluto a planet as we have historically.
At the end of the debate the audience voted in favor of Pluto's reinstatement.
That doesn't mean that the IAU will now reverse course, but perhaps the reinstatement movement will rise up with its newfound momentum.
© 2025 Newsmax. All rights reserved.