Is Pluto Really a Planet or is it Something Else?
The International Astronomical Union finally decided that Pluto should not be considered a planet. Although controversy continues to exists with IAU’s decision, under the new definition, Pluto falls short of being a planet. To be a “planet,” a celestial body must orbit around the Sun and have a nearly round shape. Pluto passes both of these tests, but it fails the third one, which is “clearing the neighborhood around its orbit.”
Although the phrase is rather ambiguous, it is believed to mean that the planet should have mass dominance within the area around it. Due to Pluto’s oblong and eccentric orbit, it cross paths with Neptune’s orbit and is twenty times as massive as the neighboring Orcus. Since it does have a comparable mass neighboring it, Pluto fails the test and is now assigned into the role of a “dwarf planet,” which has the same characteristics of a normal planet but does not have to clear the neighborhood around it. Technically, larger planets that are closer to each other would still fail as being planets, as “planet” is not really defined by the size or mass of a celestial body. Everything else in the Solar System, outside of planets and dwarf planets, is just known as “Small Solar-System Bodies.”
Despite the final decision by this group of astronomers, many people still would like to believe that Pluto is considered a planet. Some have learned all their lives that Pluto was the farthest and smallest planet in our Solar System, but essentially science is taking back what it had previously said. Others might just disagree with the IAU’s definition of “planet,” as the term originally meant “wandering stars” in Greek.
On the other side of the debate, some see Pluto’s history as a reason for why it should not be considered a planet. At the time, incorrect calculations dealing with Neptune’s orbit lead many people to believe that there must be another planet out there that was disturbing Neptune. Even though the calculations were wrong and there was really nothing wrong with Neptune, people were actively searching for another planet and eventually found it, almost by coincidence.
Some believe that Pluto should not be considered a planet due to the Kuiper belt. With tons of Pluto-like objects with eccentric orbits out past Neptune, many astronomers believed that Pluto is a Kuiper belt object and has nothing to do with the other eight planets, due to its similarities with other Kuiper belt objects. Kuiper belt objects such as Pluto are generally made up of rock and ice and have eccentric objects. They are also not coplanar like the other eight planets, which is one of the main reasons why many astronomers don’t see Pluto as being a planet.
Despite the ongoing controversy dealing with Pluto’s status as a planet, the International Astronomical Union is trying to perceive Pluto and other dwarf planets as being a subset of planets, rather than establishing them as separate identities. Through this method, those angry with Pluto’s demotion will still not be too disappointed. With current space technology improving, we should expect to discover many more dwarf planets in the trans-Neptunian object class. Although in the future Pluto will no longer be taught as a subject, everyone can be rest assured that it’s controversy will live on as it helped shape define the ambiguous term “planet.”
