Pluto Is a Planet (Again), According to New Study

ORLANDO, FLORIDA — The International Astronomical Union should ‘rescind their non-scientific definition’ of Pluto as a dwarf planet, according to a five-year study in the journal Icarus.


Pluto was controversially relegated from full planetary status in 2006 because it didn’t hit all three of a new set of planet-defining criteria.


The IAU said that while Pluto does have enough mass to ensure that it is rounded out by its own gravity, and it orbits a star, which are the first two criteria, it also shares gravitational space with other objects in its orbit, and this means it should not be classified as a planet.


The new study, however, says this definition was engineered to simplify our picture of the solar system by ruling out dozens of other large planetary objects like Eris and Makemake, and thus has reopened a longstanding debate.


Notably in the new study’s favour is the fact that Pluto is actually in no way alone in sharing gravitational space with other objects in its orbit, according to The Verge, with thousands of asteroids orbiting along with Earth, for instance.


Writing in National Geographic, however, Steven Soder of the American Museum of Natural History has previously sought to address this point by clarifying that a planet should be able to “dynamically dominate” its orbit zone, meaning that it has swept away objects out of its orbital path to the extent that it is clearly the largest object occupying that area, as opposed to sharing its orbit with nothing else, according to The Verge.


Fitting that bill, Earth is 1.7 million times bigger than all of the asteroids in its orbital zone combined, while Pluto is just 7.7 percent of the mass of all of the objects that cross its path.


However, this argument is not enough for the scientists behind the new Icarus study. They say that the definition of a planet should align with ‘geological complexity’ rather than an oversimplified ‘folk taxonomy’ which provides us with the conveniently low, ‘public-friendly’ number of eight planets in our solar system.


Under that definition, Pluto, with its thin atmosphere, complex geology, and maybe even a liquid ocean, would be considered a planet. And so would up to 150 other objects in our solar system, according to the study.