Planet or dwarf planet? Pluto and its definition as a celestial body does not stop dividing experts in the field
I am a UFO and I come from Mars, I'm waiting for the train that takes me to her on Pluto: perhaps not even the alien imagined by Rino Gaetano in his little known song would want to venture in the dwarf planet after the latest controversy that has affected its definition.
For 15 years Pluto is no longer considered a planet, a downgrade that, however, has not extinguished the scientific debates. Eight American planetologists have recently published a study dedicated to the celestial body in the journal "Icarus", an attempt at rehabilitation that has made more than one expert turn up his nose. But what exactly happened?
The study of discord
The publication traced the various ways in which the concept of planet has been defined, starting with the one used by none other than Galileo. According to U.S. planetologists, in the '900 would take over a vision too simplistic and dictated by folklore of the planets of the solar system, coming to limit the number until the historic and controversial decision of 2006, when Pluto was downgraded precisely to a dwarf planet. The study goes on to point out that any geologically active celestial body could be considered a planet, rehabilitating what has always been considered the last and farthest of the nine known.
Reasoning in this way, other celestial bodies could also be promoted to planets, starting with the Moon and even asteroids. The research was led, among others, by Alan Stern, scientific head of the "New Horizons" mission that saw NASA in 2015 with the flyover of Pluto. Such conclusions could not leave indifferent and in fact a real Pandora's box has been uncovered within the scientific community. The most "serene" opinion was that of Piero Benvenuti, former secretary general of the IAU (the International Astronomical Union, the body that has downgraded Pluto three decades ago). According to him, the proposed change cannot be accepted, because to think that the downgrading was favored by "folklore" and cultural heritage is too big an accusation.
The IAU reaction
We certainly do not have to imagine furious quarrels between academics and distinguished professors, these controversies are normally staged at a distance (as is normal). Benvenuti called the rehabilitation attempt bluntly, in a nutshell, "a ramshackle study and worse than the previous ones." The downgrading linked to folklore, then, could not leave the former general secretary indifferent, who branded the statement as "hallucinating". To distance himself from the controversial study was also Andrea Longobardo, planetologist who is part of the INAF (National Institute of Astrophysics), which has not, however, ruled out a revisiting of the definition of planet.
The history of Pluto has not had jolts for over seven decades. In fact, after its discovery in 1930, there was no doubt about its definition, at least until 1992 when the first debates began. In the Kuiper belt, the same in which the dwarf planet orbits, objects of similar size, if not larger than Pluto, have been discovered, with the consequent reclassification in 2006. It is a story that is now already 15 years old, but there are many who do not want to give up and give a "second chance" to one of the most mistreated celestial bodies ever.