Pluto is called to return to the list of planets
From the day it was discovered in 1930 until 2006, Pluto was officially considered the ninth planet of our solar system. Soviet scientists as early as the 1950s suggested that Pluto is only one of the dwarf planets that circulate in this area of outer space in close orbits. This hypothesis was fully confirmed: at the end of the XX and beginning of the XXI century, many other objects were discovered in the outer part of the Solar system.
On August 24, 2006, the International Astronomical Union first defined the term “planet”: from now on, only those objects that satisfy three basic criteria are considered to be such: they revolve around the Sun, have a spherical shape and have a “clean” orbit, that is, free from other celestial bodies. Alas, Pluto did not fit into it on the third point and astronomers attributed it to a new category of dwarf planets, along with Eris and Ceres.
After this “reform”, Pluto was added to the list of minor planets and received the number 134340 from the catalog of the Center for Small Planets. But now American scientists have stated that although there are really many other Kuiper belt objects in relative proximity to it, this criterion is practically not used in astronomical research. Moreover, many scientists in their works often call planets even those objects that do not meet the official definition.
In addition, astronomers from Florida believe that the condition of a “clean” orbit itself is quite relative, since the orbits of comets and asteroids pass near any planet. But you can’t argue with the spherical shape of Pluto, therefore, scientists urge that this be considered the main criterion and return it to the list of planets. In favor of Pluto is also evidenced by the fact that it has an underground ocean and a layered atmosphere.