Pluto and his status as a former planet is still a hotly contested issue among scientists, even more than a decade after he was titled "revoked" and reclassified as a dwarf planet. However, if you depend on a team of NASA researchers, soon, the star will once again rank among the worlds that make up the Solar System - and many other celestial bodies would be on the list too, including our Moon!

Demotion

Going back a bit, Pluto was reclassified as a dwarf planet in August 2006, after California Institute of Technology astronomer Mike Brown, Caltech, proposed a reformulation of the rules that define the planets for the International Astronomical Union.

Pluto, poor thing, was demoted

According to Mike's proposal, for a celestial body to be considered as a planet, this object must “have sufficient mass for its own gravity to outweigh rigid body forces so that it acquires a (practically spherical) shape in hydrostatic equilibrium, to be in orbit around a star, other than a planet star or satellite, and to have cleared the vicinity of its orbit. ”

For the International Astronomical Union has liked Mike's suggestion and, like our dear Pluto, meets the first two requirements, but - unfortunately - does not meet the last, being "downgraded" the dwarf planet. Having clarified what happened, according to Bec Crew of Science Alert, a group of NASA researchers published a manifesto proposing a new and more precise way to define what a planet is.

Where's Pluto?

The group is led by Alan Stern, a planetary scientist at the helm of NASA's New Horizons mission, and he said the people at the International Astronomical Union had nothing to hear from an astronomer to define what characterizes a planet. As I said, it would be the same as asking a pediatrician to do a neurosurgery. What Stern meant by this is that the organization should have listened to a planet expert to determine what a planet is, why!

Manifest

According to Bec, as Stern explained, when scientists look at an object like Pluto, they can't find any other way to call it than planet. So the team came up with a geophysical definition that, instead of sticking to the question of whether or not a particular celestial body orbits a star, evaluates the physical properties of that star.

Under the new proposal, a planet would be any round celestial object other than a star.

Thus, according to the manifesto, "a planet is a sub-stellar mass body that has never undergone nuclear fusion and has sufficient self-gravitation to assume a spheroidal form adequately described by a triaxial ellipsoid, regardless of its orbital parameters." In other words, a planet is any round celestial object other than a star - simple as that.

However, do not think that the definition the team proposes in its manifesto is arbitrary and encompasses every class of celestial object that exists throughout the universe. On the one hand, the proposal would return Pluto to its former title, and would include stars like all dwarf planets in the Solar System and even our Moon - meaning we would have a huge new list of planets as neighbors.

According to the new definition, even the moon would be classified as a planet.

However, on the other hand, the new definition would leave out all stars, including white dwarfs and neutron stars, as well as black holes. Of course, nothing has been decided on the matter, and the staff of the International Astronomical Union will have to deliberate long before reaching any conclusions about the new definition, and we will have to wait a long time to know what they have decided.

But considering that there are still so many - so many - things that we don't know about the universe yet, who makes sure that this definition doesn't end up being replaced before we are even able to memorize the names of all the stars that would make up the family of. planets that make up the solar system?