Decoding the Pluto Argument

Many of us know that Pluto is not a planet anymore. Some of us know the reason, Why so? But, not many of us would know that a team of scientists wants Pluto classified as a planet again know along with dozens of similar bodies in the solar system and any found around distant stars.

The call goes against a controversial resolution by the International Astronomical Union (IAU) that decided Pluto is only a “dwarf planet”. But the researchers argue that a rethink will put science back on the right track.

Image Source – Space.com

Pluto had been considered the ninth planet since its discovery in 1930, but the IAU, which names astronomical objects, decided in 2006 that a planet must be spherical, orbit the sun, and have gravitationally cleared its orbits of other objects. Pluto meets two of these requirements: It’s round and It orbits the sun. But because it shares its orbit with objects called “plutinos,” it didn’t qualify under the new definition. As a result, the IAU decided that the solar system only had eight major planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto was banished from the list. Now a question might pop in your mind, What are these PLUTINOS? Wait, I will explain it

Plutinos are trans-Neptunian objects, lying in the Kuiper Belt, characterized by being in 3:2 mean-motion resonance with Neptune that orbits the sun at the same speed as Pluto. The dwarf planet (Pluto) is the largest member of this group. Plutinos make up approximately one-fourth of the Kuiper Belt objects.

Image Source – Wikipedia

Anyways, coming back to the main topic, the researchers say Pluto should be reclassified as a planet under a definition used by scientists since the 16th century that “planets” are any geologically active bodies in space. Apart from Pluto, the definition also includes many other bodies like the asteroid Ceres, the moons Europa, Enceladus, and Titan.

Views of Planetary scientists

A study announced in December from a team of researchers in the journal Icarus claims the IAU’s definition was based on astrology, not science, and also that it’s harming both scientific research and the popular understanding of the solar system.“We think there are probably over 150 planets in our solar system,” said Philip Metzger, the study’s lead author and a planetary physicist at the University of Central Florida. The study comes amid research based on data from NASA’s New Horizons probe, which flew by Pluto in 2015. The probe’s revelations have revived debate about Pluto’s status,  planetary geologist Paul Byrne of North Carolina State University said.  The researchers argue the IAU definition contradicted a definition of a planet that stood for centuries. Objects similar to Pluto, such as Eris and Makemake, had been found by 2006, and so the IAU planned its definition to exclude them, Metzger said. That led to the IAU and therefore the public adopting the “astrological” concept that Earth and the other planets were few and special, instead of a better classification that would have greatly increased the number of planets, he said. The result is that most planetary scientists now disregard the IAU’s definition, he said. “We are continuing to call Pluto a planet in our papers, we are continuing to call Titan and Triton and some other moons by the term ‘planet’,” he said. “Basically, we are ignoring the IAU.”
California Institute of Technology astronomer Michael Brown, the author of the memoir “How I Killed Pluto and Why It Had It Coming,” says the IAU made the right call by correctly classifying it as a dwarf planet. “I think the IAU fixed an embarrassing mistake that had been perpetuated for generations,” he said in an email. “The solar system is now sensible.”

Some scientists support the IAU’s call of not classifying Pluto as a planet. On the contrary, there are other scientists too, who believe that Pluto should be reclassified as a planet. Well, what’s your view on this? Do let me know in the comments.

References
https://www.nbcnews.com/science/space/pluto-planet-debate-rages-rcna8848
https://www.tasnimnews.com/en/news/2021/12/31/2635773/scientists-say-pluto-should-be-reclassified-as-a-planet