In fact, the issue remains highly controversial. In your opinion, does Pluto deserve to be called a planet?
Before 2006, Pluto was considered the ninth planet of the solar system. However, at the end of the 20th century and in the early 21st century, scientists discovered more and more celestial objects with similar mass to Pluto.
Before 2006, Pluto was regarded as the ninth planet in the solar system.
As a result, the International Astronomical Union (IAU) established a new definition, stating that celestial bodies must meet certain criteria to be considered planets. Since then, the solar system has had only eight planets, as Pluto was “reclassified” as a dwarf planet.
Despite being sidelined, Pluto is not alone; it has garnered significant support from scientists advocating for its “identity” to be restored.
Recently, Alan Stern and David Grinspoon, two astronomers involved in the New Horizons project, published an article in the Washington Post, presenting compelling arguments for restoring fairness to Pluto.
It is known that in 2006, the IAU’s definition of a planet had to meet three criteria:
- It must orbit the Sun.
- It must have enough gravitational force to assume a nearly spherical shape.
- The neighborhood around its orbit must be cleared of other debris during its formation.
Because Pluto’s neighborhood is the Kuiper Belt, which contains too many celestial bodies—some of which have greater mass than Pluto—it can no longer be classified as a planet.
The Kuiper Belt – the reason Pluto is no longer considered a planet.
However, according to Stern and Grinspoon, this definition is outdated. First, if we consider all three criteria, Earth itself might not qualify as a planet, as there are still many mysterious celestial bodies in our neighborhood that have not been cleared.
Moreover, this definition does not apply to exoplanets—planets located outside our solar system. Over time, more and more exoplanets have been discovered, leading to the need for additional and unusual criteria for what constitutes a planet.
Ultimately, both experts believe that Pluto fully meets the qualifications of a planet. The simple reason is that the term “planet” should be used to describe a world with certain geographical features, rather than solely focusing on its orbit.
“We should use the term ‘planet’ to describe worlds with specific characteristics” – Stern stated.
“When we see a celestial body with features like ice mountains, nitrogen glaciers, and a blue sky with an atmosphere surrounding it, we should simply call it a planet. And Pluto is exactly like that.”
Some leading astronomers do not consider Pluto to be a planet.
However, not everyone agrees with them.
In 2017, Stern and Grinspoon proposed adding a criterion to the definition of a planet, which was “Celestial bodies that are smaller than a star.”
Unfortunately, not many scientists supported this definition, as it could mean that our Moon could also be considered a planet.
Some leading astronomers, such as Neil deGrasse Tyson, also do not consider Pluto to be a planet, firmly stating so at the end of 2017.
Overall, whether Pluto will be reclassified as a planet remains unclear; it is only known that the debate surrounding it will likely persist for a long time in the future. Nevertheless, congratulations to Pluto, because this “little guy” may have been sidelined but is certainly not alone.
